Q: I just moved to Florida and want to know if I can grow artichokes here?
A: Welcome to Florida and especially Nassau County. The quick answer is no, we do not have the completely frost free area and mild temperatures required to grow the globe artichokes you mentioned. Ideally, they prefer daytime temperatures between 70 and 75 degrees F. with night time temperatures around 50 – 55 degrees F. We might have temperatures similar in the spring but not long enough for the plant to develop the globe fruit which takes about 80 days. Globe artichokes, which are part of the Composite family, typically grow in California but I found some information from Texas A&M Extension suggesting home growers in the southern coastal regions of Texas have had some success. The immature globes are surrounded by fleshy flower-like parts called bracts. The base of these bracts are broken off, dipped in a delicious sauce and eaten. Harvesting occurs from March through May. I am attaching a wonderful article from the University of Illinois regarding some varieties which have been grown in colder Midwest environments. I have also attached a University of Florida publication with other information on the globe and Jerusalem artichoke. That said, the long answer is – it may be possible. You will have to experiment with different varieties to see what might possibly work here. Good luck and keep me posted on your progress – you might just end up being very successful.
Q: I planted asparagus crowns in 2010 and had good luck with them. I now have some fern-like bushes and need to know if I need to cut these back or let them grow. I am looking forward to a small production this year but any advice would be helpful. BB
A: I am so glad you have been successful growing asparagus here. You must have the right touch as it can be difficult to get asparagus established in Florida. Asparagus, Asparagus officinalis, is a true perennial, which means the top portion may dieback in the winter but the rhizomes, which grow underground, are still alive. The spears will show up in the spring and can be harvested for 2 – 3 months. The top “fern-like” portion you are seeing now will provide the nutrition for next year’s crop so do not cut it down. But do not worry if the top portion dies back in the cold. The spears are produced when the plant goes through a dormancy period generally caused by cold or drought and there are times when it is not sufficient here in Florida. Even if times are good, in Florida we may only have 3-5 years of production then the plant reduces the amount of spears it creates. But, if you are like me and love asparagus, even a few years is worth it. Taking into account the limited number of years spears are generated, consider planting some seeds now for a potential future crop. By the way, this is not the same plant we consider an invasive nuisance, Asparagus aethiopicus or A. densifloru, asparagus fern. http://edis.ifas.ufl.edu/pdffiles/MV/MV01300.pdf
Q: I am growing a small garden with several varieties of beans. I would like to have some of them dried. How do I go about doing that?
A: Normally beans are left in the pod and on the vine to dry. Navy, kidney, Northern, and black beans are common varieties used as dry beans. There have been few successes here in Florida because the beans prefer to dry in the pod for 120 days in temperatures ranging from 65 – 75 degrees with low humidity. That is not a condition normally describing Florida for any length of time. You could try to remove the mature pods and hang them in a cool, dry area. If you decide to try this tactic please keep me posted on your progress; it would be fun to hear you had succeeded. Beans are a very important source of minerals and fiber.
Q: I purchased three different kinds of bean seeds from various local garden centers. Some of the seeds came up quickly and others still have not germinated. What is wrong with the seed?
A: The ability of seeds to germinate or sprout is called viability. Often the seed packet will give you a percentage of the number of seeds you can expect to germinate. The higher the percentage rate on the packet of seeds the greater chance of the seeds sprouting. Some seed come coated with fungicides to protect them during their early development stages if they are susceptible to fungal diseases. Viable and dead seeds in some plant species can be separated by placing the seed in water. Living seeds will sink but dead, empty seeds will float. This is a good means of identifying dead oak and pindo palm seeds, but it does not work with all plants. Seeds of many plants can be stored and germinated weeks, months or even years. Factors affecting the viability of seeds during storage include the plant’s own genetic make-up, moisture content of the seed, temperature and humidity. It is important to know how long the seeds are stored on the shelf as some seeds may lose viability after a few weeks or a year, again depending on the plant. Most seeds prefer to be stored in cool, dry areas. You might consider ordering your seed from a reputable seed catalog company if you have had poor results from local garden centers. Propagating your vegetables from seed has a long history with vegetable growers throughout the county and a source of great pride. Be sure you choose vegetables that grow well in our area. There are certain varieties that grow well in our hot, humid summers; others do not prosper as well. http://edis.ifas.ufl.edu/vh021
Q: I planted some beans and tomatoes about ten days ago and they really are not doing very well. Do you have any suggestions as to why? What am I doing wrong?
A: July is really a difficult time of the year to plant vegetables. You might get lucky and receive some reward for your labor but it would be better to plant earlier in the year or try something next month in August. It is entirely too hot right now and the insects and diseases are at their peak. It would be better to wait a few more weeks and begin preparing your fall garden. There are many vegetable choices for fall gardening in Northeast Florida and I am sure you will achieve success. Try snap bush beans such as Bush Blue Lake, Contender or Provider. Yellow Wax bush bean variety such as Cherokee Wax is another possible choice. Consider Horticulture, Pinto, Red Kidney, Black Bean or Navy Beans for shelling bush peas. You might try tomatoes again by planting them in August. Try growing fall tomatoes and maybe you will be one of the fortunate ones. However, do not be discouraged if the tomatoes are not successful in the fall, some people have good luck, others do not. See the Florida Gardening Guide for more information on what can be planted and the time best of time of year to plant. This document was published by the University of Florida. http://edis.ifas.ufl.edu/vh021
Q: Can we grow beets here? If so, when do we plant them?
A: We indeed can grow beets in Northeast Florida. You can plant beets in our area anytime between August and February. The seeds should be planted ½ to 1 inch deep. It will take about 50-65 days until the beets are ready to harvest. Choices of seed for this area are: Early Wonder, Detroit Dark Red, Cylindra, Red Ace, Little Ball, Asgrow Wonder, Green Top, Pacemaker III, and Red Ace. Irrigation at the beginning of root growth is important but it should be reduced significantly during the end of root maturation. Overhead irrigation may be needed to ensure soil does not become too dry to the point of cracking. One 2 inch diameter beet contains 35 calories, zero fat and cholesterol, very little sodium or carbohydrates, small amounts of iron, vitamin C, fiber, potassium and manganese, and about 6 grams of sugar. The green leafy portion is a wonderful source of vitamin A. They greens can be eaten raw in a salad or cooked similar to other greens such as collards or mustard.
Q: I want to try planting beets this year in my fall garden. What varieties does the University of Florida recommend?
A: Beet is native to areas of Europe, the Near East, and Africa adjacent to the Mediterranean Sea. Beets can be planted from September until March in Northeast Florida. Tall Top, Early Wonder, Detroit Dark Red, Cylindra, Red Ace, and Yellow Detroit are all heirloom varieties recommended for our area. Just so you know, the leaves are also edible and can be added to soups, stews and salads so very little of the beet product is wasted. Tall Top provides large leaves for salad harvesting. Early Wonder is a common variety used by most gardeners as it produces a full size beet early in the season. Detroit Dark Red produces a 3 inch dark, red beet about mid season. Cylindra is a beet shaped similar to a carrot and grows about 6 inches long with a mild, sweet flavor which takes about 56 days to mature. Red Ace is an easy, reliable beet which takes about 53 days until harvest and it probably the best one to start in your garden. Golden Detroit is very sweet, does not bleed its color when cooked, and takes about 60 days to mature. Put the seeds about ½ to 1 inch deep in the soil and the soil needs to stay moist initially or the seeds will not germinate properly. If you plan to plant rows, they should be 1.5 to 2 feet apart. Good, consistent irrigation is important for root crops to form properly – but not too much! Be sure to have the soil pH tested prior to planting your fall garden as this will determine the type of calcium to add to the soil. The ideal pH range for vegetable crops is 6.0 to 6.5 – slightly acidic. However, beets are not that picky about the soil pH. It is recommended to add your calcium source 30 days or more prior to planting. The Callahan office can run a pH test any day of the week from 8am to 5pm; the Yulee satellite office is manned by a Master Gardener volunteer on Fridays from 10am to 2pm (except holidays).
Q: Is there any vegetable I can plant now (December) or am I too late? Also, I am just a beginner so I would like to start out with something easy.
A: I commend you for wanting to try gardening. You are smart to start during the cooler months as winter gardening in Florida is much easier than during the warmer months –especially for novices. I have attached the University of Florida vegetable garden guide to assist you. This publication contains information on preparation, planting, selection and maintenance of gardens. I think one of the easiest vegetables to grow here during the winter months is broccoli. Try any of the following varieties – Early Dividend, Waltham, Early Green, Packman, or De Cicco. Broccoli is an excellent source of calcium, fiber and vitamins C and A. There are other easy vegetables too such as lettuce, cauliflower, peas, and cabbage. Have fun with your garden and do not be afraid to try new things – you never know how successful this adventure may be for you. Good luck – and keep me posted on your progress. http://edis.ifas.ufl.edu/vh021
Q: Can we grow Brussels sprouts here in Florida?
A: Yes, we can grow Brussels sprouts here in Northeast Florida but producing a full harvest is as unpredictable as our Florida weather. Brussels sprouts grow best with cool daytime temperatures, preferably below sixty-five degrees. Some fall and winters we have consistently cool temperatures but one never knows. Planting time is between September and November. Brussels sprouts are related to the cabbage family. The tiny sprouts grow along the stem at the base of each leaf rather than one large head. According to Texas A&M, if you wish to collect the seeds for next year’s crop, keep the sprouts away from cabbage, broccoli or cauliflower. Brussels sprouts can cross pollinate with any of the plants in the cabbage family which would produce hybrid seeds. Purchase quality, disease free seeds. Several reliable seed catalog companies are available on-line.
Q: I know I am supposed to cover the head of my cauliflower so it will stay white but I don’t know when I should do it.
A: Although you have been successful, cauliflower can be a difficult vegetable to grow successfully in the vegetable garden mostly because it prefers temperatures in the 60 to 70 degree range. At higher temperatures, cauliflower will not head properly. It also requires adequate water and fertilizer for optimal performance. In order to maintain its flavor and firm consistency, cauliflower must be kept snowy white. This is done by tying the leaves together over the heads when the heads are between 2-3 inches in diameter. The heads should be examined from time to time to determine when they are ready to harvest. If you let them stay too long, the heads get loose and grainy, and lose much of their tenderness. In North Florida, cauliflower can be planted in the following months: January - February or August – October. The best varieties for Florida are Snowball Strains or Snow Crown. Brocoverde is a green-headed variety. Be sure to space plants 24-30 inches apart.
Q: I planted so many fruit seeds and lost so many plants I no longer know what is growing. Can you tell me if this plant is cantaloupe or watermelon? What are some good choices for seedless watermelon?
A: Well, this is the first time I have been asked that question. I am glad you brought in several samples of the leaves as it made it easier to identify. You leaf is from a cantaloupe plant. Watermelon leaves are much more lobed than the cantaloupe leaf. Cantaloupe should be grown in warm climates with low humidity. Rots can easily occur in wet, humid climates or if too much irrigation is applied too often. Cantaloupe prefers fertile, well-drained slightly acidic sandy or silt loam soil with a pH between 6.0 and 6.5. Additions of high levels of nitrogen may prevent plants from maximum fruit production and maturity. Use formulations of fertilizers similar to 6-6-6 or 8-8-8, which can be easily found at any garden center. Applications of pesticides should be done before sunrise or after dark to reduce the chance of applying it directly to bees which are essential for pollination. Seedless watermelon choices for Florida are: Crimson Trio, Genesis, King of Hearts, Merrilee III, Millionaire, or Scarlet Trio. For more information on growing seedless watermelon check out the University of Florida publication: http://edis.ifas.ufl.edu/CV006
Q: Please give me some information about Chinese cabbage. I am considering planting it here.
A: Chinese cabbage is a cool season vegetable which means it should be grown here from fall to early spring. It grows best with short days and moderate to cool temperatures (60 to 70°F). Direct seeding is possible, especially for the fall, in loamy to sandy soil. It is critical to keep the soil moist during seedling establishment. It is also desirable to have an area protected from the wind when seeding cabbage. Although cultivars will vary in their response to temperature, they can bolt or form seed stalks when the temperature falls below 60°F and injury can occur during severe freezes. It is best to prevent this from happening as it may cause the cabbage leaves to become bitter. Most Chinese cabbage is harvested by cutting the entire plant just above the soil line. Old, ragged, and decayed outside leaves should be removed. The heads or entire plants are then ready for washing, using, or storage. Chinese cabbage is a fairly new vegetable to the United States since we have been planting it for only the last 100 years. There are two common types of Chinese cabbages called the Pekinensis (pe-tsai) group or the Chinensis (bok choy or pak choi) group. Pekinensis contains celery cabbage, Chinese white cabbage, Peking cabbage, pe-tsai, won bok, napa or nappa (Japanese), hakusai (Japanese), pao, hsin pei tsai (Mandarin), bow sum and bok choi (Cantonese). The Chinensis group contains celery mustard, pe-tsai (Mandarin), pak choi (Cantonese), chongee (Japanese), and Japanese white celery mustard. Chinese cabbage can be sautéed, chopped, stirred fried and even eaten raw. The shape of the cabbages varies widely as does the taste. The Chinese and Japanese have been working on breeding programs for generations and we can take advantage of their hard work. The attached publication from the University of Florida contains specific cultivars of each of these groups – please refer to it for the best choices to plant in our area. http://edis.ifas.ufl.edu/pdffiles/MV/MV03600.pdf
Q: I want to stagger my corn plantings so I will be able to harvest corn at various times of the season. I do not want to have too much to handle at one time. So, when is the last date I should plant corn here in North Florida?
A: I commend you for staggering planting times in your home garden. It is a smart strategy which will allow you to gather the harvest at various times throughout the season without being overloaded with too much at one time. This will also allow time for canning or freezing the produce in smaller increments so it can be enjoyed all year long. The corn planting season here in North Florida goes through the end of April, therefore you have plenty of time to plant a few more rows of corn. Always plant more than one row of corn. Home gardens should have 2-3 rows of corn. Remember to plant the corn in such a way so it does not cast a long shadow on other garden plants needing full sun. If possible, plant the vegetable rows so they slightly curve to discourage soil erosion. It is important to rotate your crops, which will discourage a strong build up of insects and disease in any one planting area. Planting the same crop year after year on the same site will reduce the overall harvest and quality of the produce. Several varieties do well here such as Silver Queen, How Sweet It Is, Sweet Ice, SweetRiser, and Early Sunglow. For a complete guide to home vegetable gardening check out the University of Florida publication titled “Florida Vegetable Gardening Guide”: http://edis.ifas.ufl.edu/pdffiles/VH/VH02100.pdf
Q: Whenever I plant sweet corn it always turns out like my neighbors field corn. Any ideas why?
A: What may be occurring is the pollen from your neighbors field corn may
be reaching the silks of your sweet corn and altering the flavor. Corn
is cross-pollinated by wind-blown pollen from the male flowers or tassels at
the top of the plant to the female flowers or silks about midway up the stalks.
Each kernel develops from an individually pollinated silk. Super sweet hybrids
carry a genetic factor which results in a high sugar content. The super sweet
character is lost if the corn is pollinated by ordinary sweet corn or field corn,
so the super sweet hybrids should be planted away from any other types of corn
(several hundred feet might work best). According to Texas A & M, the flavor
of sweet corn is also highly dependent on weather conditions. If it rains within
a week of harvest time, the flavor of sweet corn is often greatly diminished.
If the corn matures during high daytime temperatures as well as high nighttime
temperatures, the sugar levels of sweet corn will be low and flavor will be disappointing.
The sugar in sweet corn is converted to starch rapidly even under optimum storage
conditions so the corn should be cooked soon after harvest. The best varieties
Q: I am growing cucumbers which have turned out bitter. Can I add something to the soil to make them sweeter?
A: This is a fairly uncommon occurrence on newer hybrid varieties. However, many of us have been experimenting with older, heirloom species which has resulted in me getting this question twice this week. Bitterness is due to the formation of two specific terpenoid compounds which are found in cucurbit plants. Cucurbit plants include squash, cucumbers, some melons, pumpkins and gourds. The terpenoid compounds can be found in seedlings, roots, stems, leaves, and fruit. There are two genes which control bitterness in cucumber; a dominant one produces extremely bitter fruit and a recessive one sometimes found in the leafy portion of the plant and in the fruit (fleshy part of the plant). It is rare for bitterness to manifest itself but when it does the bitter taste will be more heavily located in the stem end of the fruit or just below the rind or peel. Weather (cool temperatures) and environmental (shady sites) conditions may trigger the bitter taste to show up in vegetables grown in our home gardens. Nothing can be added to the soil to change the taste of cucumbers once they start to mature. Bitter taste may also occur if the cucumbers are left on the vine too long or if they are stored with other very ripe fruit and vegetables. What is the final answer? Peel the skin off the cucumber and cut off the ends, if it still tastes bitter to you then toss it in the compost bin. Be sure the plant is receiving adequate irrigation, sufficient sunlight, and pick the cucumber when it is smaller rather than larger. Consider adding in some hybrid cucumber varieties to your garden so you will have a smaller chance for bitterness to be displayed.
Q: My sister grows peacock gingers and they look so easy. What can you tell me about them?
A: I actually have several different varieties in my own yard and I love them. Peacock gingers are classified under the genus Kaempheria and are suited for USDA Hardiness Zones 8–11. They should be grown in shady sites where they will receive dappled light or full shade. Peacock gingers only grow about 6 – 8 inches high so they work beautifully as ground cover. They will die back in the winter but usually return late in the spring (between April and May) and bloom from early summer through the fall. The small, one inch flowers range from pale pink to deep lavender. Even though the flower is pretty, it is the pattern on the leaves which makes peacock gingers most attractive. The leaves can be anywhere from 3 – 6 inches long with a variety of coloring ranging from bronze to deep green. My peacock gingers have loved all the rain we have been receiving this summer but they have also grown well without receiving weekly irrigation. They are not particular about the soil type although I would suggest planting them in soil which contains a good organic mix – similar to most other perennials. Peacock gingers reproduce by rhizomes and can be divided easily. They also will adapt well to container gardening.
Q: Could you identify this plant for me and tell me how to take care of it?
A: It is often very difficult to identify plants but the sample you brought to me was easier as it had an unusual flower. You plant is a curcuma which is a genus in Zingiberaceae or ginger family. These plants are native to the warm, humid environments of south Asia. Many of the varieties can be grown in zones 7-10 but not all of them are cold hardy. Curcumas prefer partial sun to fully shaded sites. They should be grown in well drained soil as some curcuma plants are susceptible to root and rhizome rot if soil conditions are wet. The rot occurs most often as a result of overwatering during the winter months when the plant is in dormancy. Most curcumas will lose their leaves when temperatures become consistently cold but they will return in the spring. Some of the species are grown for their ornamental leaves which may be variegated or have striking red colorations. The flowers, which may be hidden by the dense foliage, come in a variety of colors which could compliment most any garden. Great differences exist between the heights of erect curcuma leaves with some reaching heights of over 4 feet while others have been developed to grow only 18 inches tall. Curcumas are so common now they are often sold in most garden centers. Consider choosing Curcuma petiolata ‘Variegata’ if you are a novice gardener because this one is proven to be a hardy species. One of the most common gingers, Curcuma longa, is a native of India is cultivated throughout for its underground stems which are dried and ground for turmeric spice. Tumeric has a bitter taste but its golden color is commonly used in fabric dyes and foods such as curry powders, mustards, and cheeses. Turmeric has been touted at providing relief for various medical cures but there is little reliable evidence to support the claims. Preliminary findings from animal and laboratory studies suggest that a chemical found in turmeric—called curcumin—may have anti-inflammatory properties, but these findings have not been confirmed in human trials. As always, before using any supplement, be sure to consult with your physician as complications can arise from drug interactions.
Q: I would like to transplant my gingers. When would be the best time?
A: The best time to transplant any perennial is soon after it has finished blooming. Some gingers are ornamental and others are true gingers, Zingiber officinale, which can be used for seasoning and cooking. Both types of ginger grow best in partial to full shade. Full sun causes browning around the edges of the leaves. True ginger root should be dug up in the fall after the green leaves have died back. The root should be dried in the shade. After is has dried, it can be cut and used for cooking. Dozens of ornamental varieties are available some of which have beautiful, fragrant flowers. Consider planting Dichorisandra thrysiflora (Blue ginger), Alpinia zerumbet (Shell ginger), Curcuma (Hidden ginger) or Kaempferia spp. (Peacock gingers). Blue ginger should be planted in warmer areas of Nassau County which would mean in cold hardiness zone 9a. The blue-purple blooms are 6-8 inches long and occur from the summer through the fall. It has the potential of reaching heights of 8 feet but generally reaches on 5 feet. Shell gingers can become somewhat weedy so consider choosing one of the dwarf variegated varieties and they can tolerate more sun than most of the others. Hidden gingers produce pink or white blooms in the summer and grow about 3 feet tall. The Peacock gingers are my personal favorite and I have several varieties growing at my front door. Everyday I come home from work I see these beautiful plants with patterned leaves and pretty purple or pink flowers. They bloom from the spring through the fall. Of course the most common of all the gingers is the butterfly ginger, Hedychium spp., which would be a lovely addition to any landscape. Ornamental gingers give us a wide variety of flowering seasons, color and height. They are extremely easy to grow and a wonderful choice for the beginning gardener. True gingers: http://edis.ifas.ufl.edu/MV067
Q: Can I grow ginger here? I left it in the refrigerator and it is beginning to sprout.
A: Obviously you are referring to the root, Zingiber officinale, and not the ornamental plant ginger. And to answer your question, yes we can grow ginger in Northeast Florida. Ginger is a perennial plant meaning it has several growing seasons but in Florida that may mean only about 2 years. It has been grown in China and the Caribbean for centuries and used for medicine and in cooking. The underground structure is called a rhizome and it can be divided into pieces about 1-2 inches long. In order for it to successfully grow each section must have at least one “eye” (much like the eye on a potato). Allow the cut pieces time to dry before planting to avoid rotting. Ginger rhizomes should be planted in the early spring but you could put them in a pot to get them started if you wanted to grow them now. The cut sections will produce a 2-3 foot narrow stalk of leaves. Gingers prefer partial shaded areas and you should plant them in a mixture of sand and cow manure. You can dig up the ginger rhizomes in the fall or once you see the tops dying.
Q: My neighbor has something called a fig vine and it has been dropping large, bell-shaped fruit. The fruit are about 2-3 inches long and it has been pretty messy. What is it?
A: The vine you are referring to is called creeping fig, Ficus pumila. The leaves of this plant are generally very small when it is young and then the leaves become longer and larger with age. It prefers shade to partial shade but it seems to handle anything except full afternoon sun. Creeping fig is highly drought tolerant but it does not perform well directly along the ocean where it might be exposed to constant salt air. I just experience the fruit drop at a location on the island and was astounded at the high fruit production from these vines. I have been told by the owner, this has been the highest amount of fruit he has ever seen but his plants have been around longer then he can remember. Creeping fig does not appear to be too picky about the soil conditions. It has been known to damage the outer stucco veneer of walls or buildings which may require repairs after a few years. Clipping the vines will keep them from getting out of control. By the way, the fruit is ornamental only – it is not edible. The publication attached is from the University of Florida – Dr. Ed Gilman. Photo is from the University of Hawaii. http://hort.ufl.edu/database/documents/pdf/shrub_fact_sheets/ficpuma.pdf
Q: I have gourds that have been ripped off the vine during the hurricane. Can I still save them and dry them?
A: Ornamental gourds are closely related to the pumpkin and squash we eat. Some of the ornamental gourds are edible such as luffa gourd (sometimes called running okra) as long as it is immature. A few of the edible squashes are quite ornamental when mature, such as the yellow crookneck squash and the turban (Turk's cap) squash. Ornamental gourds are prized for their unusual shapes and often painted and carved into useful household objects such as birdhouses, baskets or planters. They can be grown throughout Florida but in Northeast Florida, they should be planted after the threat of frost is over. If possible, ornamental gourds should be allowed to mature on the vine and once matured they should be cut from the vine using a sharp knife. If they are blow off the vine, as in your case, only mature gourds should be used because immature ones will rot. The outside of the mature gourds should be washed with mild soap and water then allowed to dry. Placing them on a screen or strong netting allows air to circulate completely around the whole gourd. Be sure none of the gourds are touching each other and rotate the gourd every few days. If soft, black spots develop on the outside it is an indication of rot and the gourd should be thrown away. Once you hear the seeds rolling around inside you know the gourd has completely dried, which may take several months. Keep them out of direct sunlight as the color of the gourd may fade. Mold may develop on the outside but that provides interesting patterns. I have a gourd with a mold pattern that mimics bird’s-eye maple – very pretty.
Q: What is kohlrabi? You have it on your newsletter list of vegetables to grow in October but I have never heard of it.
A: I have attached a publication from the University of Florida but the most in-depth information I could find came from Texan A&M. The work Kohlrabi is actually a combination of two German words, Kohl meaning cabbage and Rabi meaning turnip. This plant, along with Brussel sprouts, has been developed from wild cabbage. Kohlrabi is a biennial-meaning it requires two growing seasons, with a cool rest period (wintertime) between, in order to produce seed. Kohlrabi is an enlargement of the above ground stem which was discovered around the 16th century. The first description of kohlrabi was by a European botanist in 1554. By the end of the 16th century it was known in Germany, England, Italy, Spain, Tripoli, and the eastern Mediterranean. It is said to have been first grown on a field scale in Ireland in 1734, in England in 1837. In the United States, records of its use go back to 1806. The plant is easy to grow, is remarkably productive, and an ideal garden vegetable if one does not make the mistake of planting too much of it. Kohlrabi has a similar to the turnip but milder and sweeter if the vegetable is harvested while it is young. One cup of kohlrabi raw is about 40 calories and it contains a high amount of vitamin C. It can be eaten raw, stir-fried or added to salads. If left to grow too long it can become bitter and tough. In Europe, fancy kinds with frilled and deeply cut leaves are sometimes grown for ornament. http://edis.ifas.ufl.edu/pdffiles/MV/MV08600.pdf
Q: Can I plant some lettuce now?
A: Lettuce is very easy to grow but is best grown here in the coolest months of the year (December – February). If you want to grow from seed, be sure to plant them shallow. Start out with moist soil, but not wet. For Romaine try Parris Island Cos or Outredgeous. Suggestions for loose leaf are Simpson types, Salad Bowl, Red Sails, and New Red Fire. If you prefer a butterhead then plant Ermosa, Tom Thumb, Bibb or Buttercrunch. By the way, lettuce can easily be grown hydroponically in a green house with very limited space. http://edis.ifas.ufl.edu/hs184
This attached publication is specifically regarding romaine lettuce. http://edis.ifas.ufl.edu/mv125
Q: I would like to grow shitake mushrooms. What can you tell me about the process?
A: Before I say anything further on the subject, I just want to encourage anyone interested in mushrooms to eat only mushrooms positively identified as edible. Serious complications and even death have occurred when eating mushrooms found in the wild. I am attaching a publication by the University of Florida small farm enterprises to give you more specific information. Shitake mushrooms can be grown here in shaded areas such as pine forests. The logs should be 3 to 8 inches in diameter and about 4 feet long. There are specific procedures for inoculating the logs and keeping them away from other mushrooms as to avoid contamination. It is important to purchase your initial spores from a reputable source. Shitake mushrooms will take about 6 to 18 months before they are ready to harvest. The publication gives you specifications on inoculation sources, log arrangement, marketing, and networking websites. For the single homeowner, it would make a nice hobby especially if you start small. I have also attached a publication by the National Sustainable Agriculture Information Service on other types of edible mushrooms.
Q: I am interested in growing okra, is it too late?
A: Okra, Abelmoschus esculentus, grows best when the temperatures are consistently above 65 degrees F, which makes this pod vegetable a warm season vegetable. Okra is part of the Mallow family which includes plants such as cotton and hibiscus. Here, in Northeast Florida, okra should be planted between March and July – so you still have time to get it in the ground and reap the benefits. Okra will be ready to harvest between 60 – 70 days but it is best to harvest the pod when it has grown about 2-3 inches long. The pods will be tender and edible at this stage. Long pods around 5-6 inches are too fibrous and tough. Ideally, the soil pH should measure between 5.8 and 6.8. Okra prefers well-drained, sandy soils high in organic matter, but it can be grown in a wide variety of soils. You can have the soil pH tested at either of the Nassau County Extension offices at no cost to you. Bring in a sample of your garden soil between 10am and 2pm on Fridays (except for holidays) at the Yulee office (attached to fire station #30) or any day from 8am – 5pm at the Callahan office (near the Fairgrounds). Okra produces the highest quality and quantity when planted in a full sun area. Moisture is especially important during flowering and pod development. During prolonged dry periods, a deep soaking once every seven to 10 days with one to 1.5 inches of water should be adequate. Soaker hoses or drip irrigation tape are the best methods for applying water. The University of Florida suggests the following varieties for growing here in Florida: ‘Clemson Spineless’, ‘Emerald’, ‘Annie Oakley II’, ‘Cajun Delight’.
Q: I started my onions this month and they really have not done much. What could be wrong?
A: I will need to see some of the plants to determine what might be wrong. Please call the office to determine a good time to bring in your specimen. If your soil has not been tested within the last 2-3 years, it might be wise to pick up a soil test kit at the Extension office, the cost is only $7. Generally, bulbing onions should be stated in the fall and transplanted in January through February. However, do not give up it is possible you will see some results soon. I would also suggest you consider planting clumping onions, which can be put in anytime between August and March. Onions are not difficult to grow but the University of Florida has a limited number of choices suggested for our area. Consider choosing short day bulbing onions such as Granex (yellow) for the best results when desiring bulb onions. Opt for Evergreen Bunching or White Lisbon Bunching for bunching onions. Shallots are considered multiplying onions. If you want to plant leeks choose American Flag.
Q: I would like to plant English peas but I am concerned about whether I can grow them here in the south. When would be the best time to plant them?
A: We can indeed grow English peas here in Northeast Florida but it must be done during the cooler months of the year. It is a little too early to put them in the ground now but you could start seeds inside the house or a back porch where the seedlings will receive a stable, warm atmosphere. It is also important they receive a good amount of light initially, but never direct light. Plant the seeds in a good combination of sand, peat and composted material to encourage germination. Be sure the soil is well-drained, which means moist but not wet. Plant the seeds about 1-2 inches deep but no deeper. Cover the tops of the pots or paper cups with plastic to keep in moisture. Check the pots on a regular basis to remove the plastic as soon as green leaves appear. UF/IFAS encourages planting English peas in the ground outside between January and March. It will take about 6-8 weeks before you will be able to begin harvesting your peas. Wando and Green Arrow are two varieties which produce well here in Northeast Florida. If you produce more than you can eat, consider freezing the excess. Attached is a University of Florida publication on how to properly freeze vegetables: http://edis.ifas.ufl.edu/pdffiles/FY/FY71900.pdf
Q: I have found this pretty ground cover throughout my yard in small patches. What is it?
A: This is a native perennial wildflower, which usually blooms from the spring through the fall, but we have had such a mild winter this year, it just never went into dormancy. The plant is called Innocence, Roundleaf bluet, or Fairy Footprints, Houstonia procumbens. The genus comes from a famous botanist, Dr. William Houston, who collected plants in South America. The species name procumbens refers to the flat growth habit. This pretty plant is found throughout most of the southern states from Louisiana to North Carolina It is commonly found growing in sandhills, dunes, flatwoods, hammocks and disturbed sites throughout Florida and we should probably be propagating it. Some people often consider it a weed in their lawns and work hard at trying to remove it. It is suitable for cold hardiness zones 7 to 11. It can be grown in any variety of light conditions from full sun to partial shade but produces best when it receives adequate irrigation or rainfall. However, it is growing in my neighbor’s yard and his house has been abandoned for well over 2 years – no water! Innocence has many beautiful patches in his yard so I would say it also tolerates low water conditions too.
Q: My potatoes have cracks in them. What causes this and how can I correct it?
A: The good news is the cracks are not caused by an insect or disease but by physical conditions in the soil and climate. The growth of the potato has alternating times of good nutrition and water followed by drought and temperature changes or such environmental conditions. Some potato varieties are more susceptible than others. For instance, ‘Atlantic’, used for making potato chips and ‘Red Lasoda’ for cooking often produce cracked tubers. ‘La Chipper’ and ‘Harley Blackwell’ are not as susceptible but they have been known to produce cracks during hot, wet years. So what can you do? There are a few things to reduce the potential of cracked potatoes. The most important thing is to keep soil moisture consistent. Not too wet, but not too dry. Having said that - not too much can be done about excessive rain like tropical storm “Debbie” but be sure irrigation is not the culprit. However, when the tubers are growing quickly (usually later in the season), they will need more water to stay healthy. Space plants in even rows and equal distances from each other. Overcrowding potatoes is not a good practice for strong plant and tuber growth. Be sure fertilizers are applied evenly as well. Attached is a publication from the University of Florida on this cracking problem. http://edis.ifas.ufl.edu/pdffiles/HS/HS18200.pdf
Q: We tried last year to grow pumpkins and gourds with no success. The pumpkins would flower then essentially rot before turning into fruit. The gourds didn’t do much of anything. I was wondering if there’s a particular kind that does better.
A: Pumpkins and gourds are from the same family and have been grown in our area with much success. However, the site needs good drainage, full sun and good air circulation. Pumpkins especially need plenty of room to grow and it takes about 4 months to mature. According to J.M.Stephens, a retired professor from UF, select such varieties as 'Big Max', Connecticut Field', 'Small Sugar', 'Spookie', 'Cinderella' or 'Atlantic Giant'. There are ornamental pumpkins available if you only want the look but not the food product. Here in North Florida, pumpkins should be planted between March and April or wait until August. Seeds should be planted in a row about 1-2 inches deep and 3 - 6 feet apart. Each row should be spaced 5-7 feet apart from each other. So you can see how much room they require. Avoid overhead irrigation if possible to help control any fungal growth, drip irrigation works best. The problem of producing blooms but not fruit is generally the result of having no bees to pollinate your plants and all squashes, cucumbers, and pumpkins require insect pollination. If you don't have enough bees around to pollinate your plants then you must pollinate them yourself. Take a fine paint brush, one an artist would use, and once the flower opens simply dust the pollen from the male flower onto the female flower. If you don’t know which is the male and female flower, don’t worry, just stroke the paint brush in each of the flowers and some pollen should be transferred. Think of yourself as one great big bee! Avoid the overuse of insecticides as that often contributes to killing off of the important bees and beneficial insects. Check out Dr. Stephens’s publication for more specific information on pumpkins: http://edis.ifas.ufl.edu/MV116 and gourds: http://edis.ifas.ufl.edu/mv073
Q: Can we grow rhubarb here in Northeast Florida?
A: Rhubarb can be grown here but it is somewhat difficult to do so successfully. Rhubarb prefers summer temperatures to not exceed 75 degrees and winters temperatures to be below 40 degrees Fahrenheit. As you know, many of our spring days are well over 75 degrees and although we may often dip below 40 degrees in the winter, we have been known to have temperatures in the 70s. Our traditionally warm winters encourage the tops to continue growing rather form the stalk. There are ways to artificially force the stalks to grow properly and the attached publication should help it you decide to try growing rhubarb. http://edis.ifas.ufl.edu/mv124
Q: I need to lower the pH of my soil for vegetable planting. My soil test from the University of Florida Extension soil lab said I should use sulfur, but I cannot find it anywhere. Do you have any ideas?
A: I have adapted the answer to this question from a publication titled, “Soil pH and the Landscape or Home Garden” by Shober and Denny. The full publication is attached at the end of this answer. Vegetable gardens prefer the soil pH to be between 6.0 and 6.5. If the soil is highly alkaline (over 7) then it might be necessary to raise the pH. It is difficult to bring the pH of the soil down from an alkaline state as the soil has the ability to buffer the acid and keep the pH high. In fact, lowering the pH will probably only be lowered on a temporary basis. Much of our soils come from limestone which are naturally pH levels. When you consider the high pH of our city water or well water you can see how difficult it would be to maintain a low pH. Adding elemental sulfur will lower the pH temporarily and only at the site of application. Repeat applications will probably be necessary for best results. However, one must be careful not to add too much or too often as this can damage the plants. Never apply more than “5 to 10 pounds of sulfur per 1,000 square feet per application.” Watch the plants carefully to determine if damage is occurring. Some other choices for lowing soil pH are ammonium sulfate, iron sulfate, or aluminum sulfate. Do not use calcium sulfate [gypsum], magnesium sulfate [Epsom salt], or potassium sulfate. Some of the manures will actually raise the soil pH as they contain materials with high alkaline products. http://edis.ifas.ufl.edu/ss480
Q: With all the new rules about lowering the phosphorus on fertilizers I am concerned about my vegetable garden. What kind of fertilizer should I use? Do I use the same one I use on my lawn?
A: You have asked some very good questions. Those of us with home gardens should use a complete fertilizer such as 8-8-8 or 10-10-10 (N-P-K), which will contain nitrogen, phosphorus and potassium. Notice each of the elements is applied in equal amounts. Vegetables are high users of fertilizer elements and it is often important to provide additional elements not found in our sandy soils. You also brought up an important point regarding the use of lawn fertilizers on other plants. We would suggest you never use the same fertilizer applied to lawns on vegetables, palms or fruit trees. For the most current research information on appropriate fertilizer applications please contact your local Extension agent.
Q: When can we plant spinach in Northeast Florida?
A: Spinach contains large amounts of minerals and vitamins, especially vitamin A, calcium, phosphorus, iron and potassium. Spinach also has high levels of protein and therefore a wonderful addition to any diet. Ninety-one percent of spinach weight is water. A serving of spinach contains 3.2 grams of protein, 4.3 grams of carbohydrates, and 0.3 grams of fat. It also contains Vitamin A, and C, thiamin, riboflavin, and niacin. Calcium, phosphorus, iron, sodium, and potassium are also found in spinach greens. Some specific spinach cultivars to plant are Virginia Savory, Melody, Bloomsdale Longstanding, Tyee, Olympia and Malabar. Planting should be done in October and November so you definitely asked at the right time! It takes about 45-60 days to harvest. Seeds should be planted about ¾ inch deep. Avoid overhead irrigation to reduce the potential for disease. The biggest insect problems are aphids and leafminers. Aphids and leafminers are best controlled by using ultra fine horticulture oil which can be purchased at most any local garden center. Attached is a publication from the University of Florida/IFAS on Malabar spinach: http://edis.ifas.ufl.edu/mv138
Q: Something is boring into my squash and cucumber plants. What is it and what can I do about it?
A: Several beetles (some spotted or striped) have been known to cause damage to the cucurbit plant family, which includes melons, squashes and cucumbers. The larvae of these beetles feed on roots of the plants as soon as they start to grow by boring into the roots and stems. The plant can die immediately or the feeding may cause it to be stunted which reduces the potential output of the plant. Often these beetles survive the winter, waiting for the next season of plants to arrive. During the growing season, the adult beetles feed on the nectar, leaves, fruit or flowers of the plant but they do far less damage than larvae. Another serious problem with cucumber beetles is their ability to transmit fungal, viral and bacterial diseases. Infected plants eventually wilt and die. If you find your squash or cucumbers have the wilt or root rot, they should be removed and destroyed. Next year consider choosing a variety of cucurbit seed which has proven to have some resistance to these diseases. Handpicking to remove the beetles is time-consuming but works well. Eliminate weeds in and around the garden as they often supply an additional food sources for the adult beetle. Some over the counter insecticides may give you some control over the adult beetle but once the larvae are in the stem or root, little can be done. A granular insecticide works best when applied at planting or soon afterward.
Q: My squash is beautiful this year, it has plenty of flowers and will put out a small squash but it soon falls off. I have no squash. What is wrong?
A: Most garden vegetables such as beans, peppers or tomatoes have complete flowers. This means that each flower has both male structures and female structures on the same flower. The squash family - cucumbers, squashes and melons - has incomplete flowers. These plants have either male or female flowers. Incomplete flowers need some help in pollination and usually that help comes from bees or other pollinating insects. Ultimately some of the bees may come around and pollinate for you, but you can help the process along by hand pollinating. Take a small soft paintbrush and transfer the yellow pollen from the male flower to the female flower. The female flower will have a swollen structure at the end of a stalk in the middle of the flower. Be sure to transfer the pollen from the male flower to the tip of the stalk in the female flower. Within two or three days you should know whether you were successful.
Q: Our local community garden in Hilliard has produced a zucchini that is over 3 pounds. Can you tell me the largest local zucchini recorded?
A: What a fun question. This is just the kind of question that makes the internet worthwhile. I checked the University of Florida Vegetarian Newsletter dated April 2005. According to this publication the record winning zucchini was a Park’s black zucchini weighing at 14 pounds 10 ounces by grower in Nassau County named Lynch. This record was set in 1999. A hybrid zucchini weighed in at 16 pounds 6 ounces by a Marion county grower in 2001. Now you have your work cut out for you. I would encourage all of you to plan on a fall garden and then you can bring in your beautiful harvest to the Northeast Florida County Fair in October where it could possibly win a blue ribbon. I would love to see the community come together and show the rewards of their labor. Just this year the record for largest sweet potato and turnip were broken. Although retired, Jim Stephens still keeps up with Florida’s biggest vegetables as one of his Emeritus Professor duties. The system he employs still requires the assistance of Extension agents in each county following guidelines established in 1989. Prior to that year, no one kept records of big vegetables grown in Florida. Palm Beach County holds the most Florida records with 12 out of the 53 kept. The runner-up is Suwannee County with eight records. If you are interested in the Vegetarian Newsletter check out this website for a printable version http://www.hos.ufl.edu/vegetarian/index.htm
Q: My summer squash is producing loads of fruit. The problem is they only get the size of my first pinky finger joint and then they fall off. What is wrong?
A: I suspect your squash is not getting pollinated. Squash, in addition to all the cucurbits like watermelon and cucumbers, have male and female flowers. In order for the female to produce completely mature fruit; her flower must be pollinated by the pollen from male flowers. The pollen from the male flowers is deposited on the female flowers as the bees go from flower to flower gathering nectar. Unfortunately, we have been seeing the populations of bees diminishing in greater numbers every year. We are not certain of the root cause of the decline in bee populations but we have certainly been seeing the result - fewer fully developed fruit. What can we do? First, you can pollinate your own plants. I know it sounds crazy but since you have a small garden it can be done by hand. Take a small artist paint brush and go from flower to flower. This will transfer the pollen manually. Your flowers will ultimately produce fully developed fruit. Of course, this is not practical for farmers therefore missing bees is a serious threat to their fruit and vegetable production. Those of us with home gardens can also use pesticide wisely. Overuse of insecticides can cause pest resistance and be harmful to bee populations. Use pesticides judiciously for the best results now and in the future. “The Label is the Law.”
Q: I have been reading about the benefits of eating sweet potatoes and I think I would like to grow it here. What do you recommend?
A: The sweet potato, Ipomoea batatas, originated in tropical America and ranked second only to the Irish potato as an important vegetable until World War II. The sweet potato is a good source of sugars, carbohydrates, calcium, iron, and other minerals and vitamins, particularly A and C. The edible part of the sweet potato is a swollen storage root. The common sweet potato requires a great deal of garden space because it produces long vines. However, there is a cultivar (‘Porto Rico’) which can be more bush or bunch-like and these can be grown in containers. Container grown sweet potatoes will require additional care such as watering and fertilizing but for those of us with limited sunny spaces, bush sweet potatoes are a viable option. Sweet potatoes need warm days and nights so they are considered a warm season vegetable here. The soil pH should be between 5.6 and 6.5, typical of most vegetables. If the soil pH goes near or above 7, the plants will be more prone to diseases. In Northeast Florida, we recommend planting sweet potato between March and June; it will take about 120 – 140 days to mature for harvesting. Sweet potatoes are grown from slips (transplants) and it is critical for home gardeners to purchase disease-free plants from reputable growers or garden supply stores. Like most vegetables, it is wise to rotate crops and avoid planting the same vegetable in the identical spot repeatedly. If you grow them in containers, then we would suggest you replace the soil each year. Consider applying ½ your normal fertilizer amounts to the soil 10-14 days prior to planting and mix it well into the soil. The other ½ of the fertilizer can be applied along the sides of the mound (side-dressing) after the plants become established or show evidence of new growth. If you plant the bush variety in containers then incorporate the fertilizer into the top few inches of the soil – do this manually (by hand) to avoid damaging tender roots. There is another tropical sweet potato, often called the Cuban sweet potato, which can be grown here too. It has white flesh rather than the common orange or yellow flesh we are accustomed to seeing in the grocery stores and in our candied sweet potato recipes during the holidays. Attached is a complete publication from the University of Florida on the Cuban sweet potato: http://edis.ifas.ufl.edu/mv030
Q: Are the words sweet potato and yams interchangeable?
A: This is the season when this question gets asked most often. I took the following information from Texas A&M Extension. Hopefully, this will answer your question. “Several decades ago when orange flesh sweet potatoes were introduced in the southern United States producers and shippers desired to distinguish them from the more traditional white flesh (potato) types. The African word "nyami" referring to the starchy, edible root of the Dioscorea genus of plants was adopted in its English form, "yam". Yams in the U.S. are actually sweet potatoes with relatively moist texture and orange flesh. Although the terms are generally used interchangeably, the U.S. Department of Agriculture requires that the label "yam" always be accompanied by "sweet potato." As a main dish or prepared as a dessert, the sweet potato is a nutritious and economical food. One baked sweet potato (3 1/2 ounce serving) provides over 8,800 IU of vitamin A or about twice the recommended daily allowance, yet it contains only 141 calories making it valuable for the weight watcher. This nutritious vegetable provides 42 percent of the Recommended Daily Allowance (RDA) for vitamin C, 6 percent of the RDA for calcium, 10 percent of the RDA for iron, and 8 percent of the RDA for thiamine for healthy adults. It is low in sodium and is a good source of fiber and other important vitamins and minerals. A complex carbohydrate food source, it provides beta carotene which may be a factor in reducing the risk of certain cancers. When buying sweet potatoes select sound, (deep orange) firm roots. Handle them carefully to prevent bruising. Storage in a dry, unrefrigerated bin kept at 55-60 degrees F. is best. DO NOT REFRIGERATE, because temperatures below 55 degrees F. will chill this tropical vegetable giving it a hard core and an undesirable taste when cooked.” Sweet potato, Ipomoea batatas, is a dicot and a true root from the morning glory family. The flesh is moist and sweet containing high levels of beta carotene. On the other hand, yams, Dioscorea species, are monocots and the tubers are dry and starchy. Most of what is produced, grown and sold in the U.S. is the sweet potato.
Q: My friend grows wonderful tomatoes so I decided I would try it. He told me to get the determinate type for my small back yard. I was too embarrassed to ask him what he meant. Can you tell me?
A: Determinate tomatoes are the smaller bush type which generally only grow to about 4 feet tall and can easily fit in the small support cages sold at most garden centers. The most common variety of determinate tomato is ‘Celebrity’ which is a nice, medium sized tomato. Your friend was probably thinking since the determinate tomato would take less space it might be easier for you to work with as a beginning gardener. Indeterminate tomatoes are the true vine types which under proper conditions (warm weather) can continue to grow, flower and produce fruit until the first cool weather appears. Indeterminate tomatoes may reach 10 feet or more in length, if conditions are perfect. You would need plenty of room to grow this type of tomato and provide ways to stake the heavy vines. Large support cages are available but they may not be sufficient if you do not prune and pinch sucker formation. You could also plant determinate tomatoes in the late summer and possibly have a supply of fall tomatoes too. I have done this and some years are more successful than others. But no matter which one of the tomato types you choose, nothing tastes as good as a home grown tomato – you will not be sorry you made the effort.
Q: I planted tomatoes and beans a few weeks ago and they are not doing well. What is wrong?
A: Since this is July in Florida, it is a little late or too early – depending on how you look at it for the plants to produce fruit. Tomatoes and beans should have been planted between February and April in the spring or you can wait until next month (August) to plant a fall crop. Plus it is too hot for tomatoes or beans to produce efficiently. Insects and disease are at their peak performance now and vegetable plants are normally on the decline. I am including a publication on growing vegetables in Florida from the University of Florida/IFAS. This publication contains a chart on when to plant vegetables here in Northeast Florida, how to prepare the ground, when to water, how to fertilize and much more information. Feel free to contract me if you need more information. http://edis.ifas.ufl.edu/vh021
Q: Will you give me a list of heirloom tomatoes to grow in Florida?
A: A growing number of garden enthusiasts are becoming interested in producing our own tomatoes. There are several reasons for the increased appeal in gardening which involve food safety issues, reduced cost and better flavor. According to Taylors Guide to Heirloom Vegetables, a tomato must meet three criteria to be considered an heirloom variety: the variety must grow “true to type” from seed saved from each fruit; seed must have been available for more than 50 years; and the tomato variety must have a history or folklore of its own. Tomatoes are labeled “IND” for indeterminate or “DET” for determinate. The indeterminate types are vines which will continue to grow and produce until cooler temperatures arrive making a favorite for many home growers. These vines will need to be staked or allowed to grow on a trellis. You may consider growing them from a hanging basket but the larger beef steak varieties may become too heavy. Tomatoes require about 1-2 inches of water a week, be careful not to overwater them as they can develop a root rot. Avoid over-head irrigation whenever possible. There are numerous seed catalogues available for heirloom tomatoes such as Mary Ann which is a classic pink-orange beefsteak tomato, Green Zebra for salads, Nebraska Wedding or Eva Purple Bell. Look for varieties able to handle heat and humidity in addition to demonstrating disease resistance. For more information on growing tomatoes in Florida please see the attached University of Florida publication is titled “Tomatoes in the Florida Garden”: http://edis.ifas.ufl.edu/vh028
Q: What is causing the white lines all over my tomato leaves?
A: Once you brought a clipping of the tomato leaves into the office, the culprit was easy to identify. The cause of the white lines is probably the American serpentine leafminer, Liriomyza trifolii. The American serpentine leafminer is the larval stage of a very tiny fly. The eastern part of the United States has had this insect chewing on our vegetables for many years but it has just been introduced to California which means it will not be long before it is found throughout the southern states. The good news is leafminers do not live very long and their life cycles require 3 – 4 weeks. Damage done by the females feeding and puncturing holes in the leaf tissue causes a yellow spotting. Once the egg is placed in between the leaf tissue it develops into a larva which feeds on the leaf tissue. This causes the distinctive white lines along the upper leaf tissue. It only takes about 3-4 days for the egg to develop into a larva. The feeding habit of this insect does reduce the ability of the leaves to produce carbohydrates and heavy feeding may cause the leaves to drop but it does not cause the death of the plant. The holes produced by the female have the potential for allowing in fungi, bacteria or viruses which can in turn cause greater damage to the plant. Parasitic wasps are important natural enemies of this fly and therefore using broad spectrum pesticides on a regular basis is not advisable. It is also important to reduce the weed population around garden at they are often the source of many insect pests. At the end of the season it may be advisable to bury the crop as leaf miners have difficulty surviving in deep soil. One study by Price and Poe in 1976 indicated natural enemies to the leaf miner (predators and parasitoids) were less likely to be found around tomatoes grown in plastic mulch and tied to stakes. As an alternative, consider using organic mulches such as pine straw, shredded oak leaves or newspaper.
Q: My tomatoes are cracking in circles around the top. What causes this to happen?
A: There are two different kinds of cracking commonly found on tomatoes. One of the cracks starts at the stem and flows downward toward the blossom end. This type of downward crack is called a radial crack. The other crack, which is the one you have, makes circles around the top of the fruit. It is possible to have both types on the same fruit. Cracks are caused when the fruit internally grows more quickly than the outside. This fast internal growth spurt causes the external skin layer to split open forming a crack. There are varieties which have a resistance to cracking but that does not mean they cannot crack only that cracks will probably occur later in the maturing process. Environmental conditions such as huge temperature differences and/or inconsistent irrigation contribute to the formation of the cracks. Not much can be done about the temperature variations especially when fruit is maturing during the spring however irrigation can be controlled by the home grower. Just be sure to water your tomatoes consistently but remember too much is not a good practice either. The vegetable is still safe to eat so there is no need to throw it away. The attached photo is from UF/IFAS.
Q: My tomatoes have been doing fine except they have just recently begun to split at the top. What is wrong with them?
A: I believe with the large amount of rain we have been receiving lately the tomato was unable to adjust. This means the water entered into the fleshy tissue too quickly and caused the external tissue (skin) to crack or break. The tomatoes are still edible but I would remove them from the vine immediately if they are ripe. All fruiting trees, shrubs and vines prefer even amounts of water throughout the fruiting process in order to produce perfect, whole fruit. But we cannot control when, where or the amount of rainfall; we just have to live with it.
Q: My tomato plants have wilted from the top. They look like they need to be watered but I know they have been getting enough water. I cut the stem like you suggested and I see a brown ring. What does it mean?
A: It sounds like Fusarium wilt. The earliest symptom is the yellowing of the older, lower leaves. It is a soil borne fungus that attacks tomatoes and other crops. The yellowing process gradually includes more and more of the foliage and is accompanied by wilting of the plant during the hottest part of the day. The wilting becomes more extensive from day to day until the plant collapses and dries up. The vascular tissue of a diseased plant is dark brown in color. This browning often extends far up the stem and is especially noticeable in a petiole scar. This browning of the vascular system is characteristic of the disease and generally can be used for its identification. Fruit infection occasionally occurs and can be detected by the vascular tissue discoloration within the fruit. It is controlled only through the use of resistant varieties. Before you plant a variety, make sure it is resistant to Fusarium wilt. This resistance is denoted by the letter F after the name. Example: Celebrity VFN. A 5-7 year crop rotation will greatly reduce losses on infested land or grow the few plants you have in pots.
Q: My tomatoes have scarring on them. They are hard and don’t fully ripen. What is wrong with them?
A: After bringing in examples of your tomatoes, it was easy to identify this physiological problem called cat face. Physiological conditions are caused by weather or climate and therefore no application of pesticides is recommended. The symptoms are malformation and scarring at the fruit’s blossom. This scarring can coincide with empty cavities toward the center of the fruit. Brown bands of scar tissue usually are located between the swelling tissues. Some cultivars are more likely to show cat facing than others, such as the large, beef tomatoes or some Celebrity varieties. Prolonged unseasonably cool weather may be one of the causes and we had an unseasonably cool spring this year. Excessive nitrogen fertilizer may also aggravate the problem. Cat face also may follow exposure to growth-hormone-type herbicides such as 2,4-D. It is always wise to avoid spraying herbicides in the vicinity of vegetable or flower gardens.
Q: My tomatoes have been ripening but the ends have turned black and mushy. What is wrong?
A: I have had a deluge of tomato problems but this one is very common. It is called blossom end rot. The first thing is to be sure the tomatoes are being irrigated on a regular basis. Remember not to over-water but irrigate at the whole root area. Blossom end rot can also be caused by a combination of lack of water and calcium. In addition to watering properly, add calcium to the soil around the root area. Use calcium nitrate but not the calcium found in ammonia fertilizers. Remove the infected fruit but do not be tempted to prune away large portions of the vine. Addition of mulch may also prove beneficial at keeping the root area moist and temperatures at the roots moderate.
Q: What is wrong with my tomato leaves?
A: The long thin lines on your tomato leaf are probably caused by the vegetable leafminer, Liriomyza sativae Blanchard. The information I am giving you is adapted from a University of Florida/IFAS publication called, “Vegetable Leafminer.” This insect is found commonly in the southern United States from Florida to California. It cannot survive cold areas except in greenhouses; therefore the vegetable leafminer is found only in southern states. Eggs are inserted into plant tissue just beneath the leaf surface and hatch in about three days. Females may deposit eggs at a rate of 30 to 40 per day, which potentially means they can deposit up to 400 or more eggs in their lifetime. An application of foliar insecticides may be require more than once. Many organophosphate and carbamate insecticides are no longer effective. Overuse of the pesticides listed above may kill beneficial insects which keep the leaf miner fly under control. As a result, leafminer outbreaks sometimes increase when pesticides used. Some crops vary in susceptibility to leaf mining, but they are commonly found on several varieties of tomato, cucumber, cantaloupe, and beans. You might consider using horticulture oil for control. Be sure the product can be used on vegetables and follow the directions on the label. Removal of some of the leaves may help, but be sure you don’t remove too many. Although tomatoes are not the easiest crop to grow because they require a lot of attention, many of us feel the effort is well worth it once you taste a home grown tomato. Yum!