Gardening with Gary

Gardening Advice from an Expert

Tomatoes

Deb writes~
I bought some Roma tomato plants. I want to know what is the best time of the month to plant them into my garden. How much water do they need? What is the best soil to use in the garden beds?

A. Plant this wonderful tomato, great for making tomato paste, outside after your last frost date. If you do not know it, contact your local cooperative extension agency, part of the Ag department.

Plant them in a well-drained, rich in organic material, soil. Add humus, compost, dried leaves, peat moss, little steer manure and/or blood meal. Spade it down at least two feet and remove any stones or limbs.

Prepare the soil well and it should not be necessary to fertilize the plants again for a month or so. Overfeeding can encourage too much foliage growth instead of fruit production. However, should the plant leaves begin to turn a little off color during the growing season, then a light feeding may be necessary. Use tomato fertilizer or vegetable garden food for this feeding. I recommend a 20-20-20, not a 30-10-10...too much Nitrogen which leads to lots of green foliage and little fruit.

When possible, use the irrigation method, letting an open hose run at the base of the plants. In other words, try to keep the water off the leaves. Water heavily, then allow the soil to dry considerably before rewatering.

It is not necessary to remove suckers from tomatoes. Nor is it necessary to prune them, unless the foliage gets too thick, making a need to get more air and light into the plant. Late in the season, when it is obvious that the top flowers will not have time to produce fruit, go ahead and prune them back so the energies of the plant are devoted to the development of the fruit already on the plant.

There are several ways to provide support for tomato plants. In the past, the most popular method was to tie the plants to stakes as they grow. Many growers still do this, but consider the wire cages available to support the vines.

Painter writes~ When is the best time to start tomato seeds?

A. One mistake many folks make when starting seeds indoors is doing so too early. For instance, tomato seeds need to be started 6 to 8 weeks before you will set them outdoors in the garden. Yet, you cannot plant them outdoors in the ground until spring frost is over.

If you are in Zone 6, where the last spring frost is about May 15, count backward from there. March 20-April 3 is about the right time to start. Add another week for germination, and you have the indoor planting date for your tomatoes: March 13- March 20.

If you start them in January, as some folks do in their excitement and desire for spring, what happens? You get plants that really want to be outside but can't because of the weather. They need bigger and bigger pots, and get taller and taller. It can be tricky keeping these plants healthy indoors and giving them the continuous bright light, water, temperature, and nutrients they need until their outdoor planting date arrives. If you have a greenhouse, no problem. But if not, wait longer; you'll have better results when plant management is a new experience for you.

Terry writes~ I have a 4 x 12' raised garden using landscaping timber. The first year (3 years ago) my tomatoes did great, but the last 2 years the tomatoes have produced little. Last year they got tons of root rot and fungus all up the stems and I had to pull them. I don't have a lot of room to rotate the crops so this year I have pulled all the soil out and I'm looking for what soil combination I should put back in there. How much fertilizer, lime, types of potting soil, loam, sand, etc... I live in Charlotte, NC. I have found that Early Girl tomatoes work best do you have another variety I should try?

A. You really need to rotate your crops. Tomatoes are the worst as to this neglect. Pathogens in the soil stay from year to year and reduce your plants to rot. There are two pathogenic fungi that can cause wilts in plants: Fusarium and Verticillium. When you purchase seed or tomato plants, look at the variety name and the letters that follow. Most varieties are VFN resistant, which means they are resistant to Verticillium, Fusarium, and nematodes. Use varieties that are VFN resistant.

Also, make sure that your tomatoes are not planted near a walnut tree. I learned the hard way that walnut roots secrete a poison which led to my plants wilting and dying after the roots had grown down below after about two months. I had to move my garden away!

Four suggestions from Dr. Helene Dillard and Dr. Steve Reiners, NYS Agricultural Experiment Station, Geneva, NY:

1) The first control measure is to purchase or produce disease-free transplants. Don't purchase tomato plants that have spots on them or that are yellowing or wilting.

2) Consider the location in your garden: it is best not to plant tomatoes in the same area in consecutive years.

3) Research has shown that placing straw, plastic, or paper mulches around the base of the tomato plants will help reduce development of disease. Mulching will provide a physical barrier between your tomato fruit and any disease organisms that may be lurking in the ground.

4) If disease is present on your tomato plants, spread of the disease can be reduced by using fungicides that are available from home garden stores.

Avoid the common mistake of overfeeding your tomatoes. They thrive in soil that's rich in humus for extensive, well-nourished root systems and potassium (K) for strong stems. Add too much nitrogen (N) and you'll have a big, lush plant with very little fruit. Brandywine is a very good hybrid, an heirloom [over 40 years old].

Homemade compost typically supplies all the phosphorus (P) your tomatoes need for good flowering and fruiting. If a soil test indicates a serious phosphorus deficiency, add rock phosphate to your tomato-growing beds next fall. Surround your plants with a layer of straw, leaves, dried grass clippings or pine needles and it will keep the plants' roots cool, prevent weeds from sprouting around them and retain moisture in the soil. Because these mulches keep the soil cool, don't apply them until after the soil warms to 65 degrees F. Consider Healthy soil is the key to healthy crops and health-enhancing foods. Conventional tomato growers never plant tomatoes in the same soil two years in a row because the accumulated disease pathogens will destroy the roots of the second crop.

Assistance from: Organic Gardening Magazine and The Sustainable Farming Connection.

Bob writes~ I am starting tomato plants from seed. They have 4 leaves on the top of each. Is it OK to fertilize lightly at this point or wait until later? What would be a good food for them at this point?

Give the seedling a half strength fertilizer. Anything strong will burn the very tiny root hairs and lead to collapse of the seedlings and then death. Water is important too, but be careful in making sure that the top soil dries a bit between waterings or you risk the spread of the damping off fungus.

Use something delicate, as Hyponex or Miracle-Gro, at 1/2 what the label calls for. No need to rush into a lot of fertilizing at this point, since the soil medium in which they are planted contains nutrients to enable them to grow well for quite while.

Also, be sure when you are getting them ready for planting outside to gradually acclimate them to the conditions by placing the trays outside in the shade for an hour a day, then two and then three, so as not to shock the fragile seedlings. This is called hardening off.

M Kerik writes~
My Daughters bought me large potted tomatoes for Mother's Day (15"-20" pots) all staked. Can these remain in the pots or is it better to replant in soil? The one plant is HUSKY RED, and the other is BIG BEEF.

A. That is up to you. I have grown and seen some wonderful full-bearing tomatoes in large pots on patios and balconies. There is nothing wrong with this method. I do warn you that the watering must be watched. Clay pots allow moisture through the sides, so if the weather is dry, check them daily for water. Water deeply so that it flows out the bottom holes. This flushes out salts which build up and harm the roots.

Feed them as you would any vegetable planted in the garden. There are very good specific vegetable fertilizers available, or else give them a food high in the middle number. The first number, Nitrogen, can cause too much foliage growth and possible blossom drop. Follow the label directions.

Keep the stems tied loosely in case of winds. Give them as much direct full sun as possible. They bear poorly in cool settings and shady locations.

Sally writes~ I have a problem my tomato leaves are curling really tight. They did this once before only one plant and then is was OK, but this year they are all doing it. Please tell me what to do.

A. Leaf curl is common. Almost all modern hybrids have leaves that curl, so do some heirlooms. Leaves also can curl if it is too hot, too cold, too dry, too wet or there is a heavy fruit burden. Leaf curl is to be distinguished from leaf roll, a common condition seen early in the season when root and foliage ratios are out of whack. As the plants mature this goes away.

What comes to my mind what curls and kills the leave of tomato plants is a tobacco virus. Is there someone who uses tobacco products touching the plants or even getting close to them? Is someone growing tobacco in your neighborhood? Tomato plants are terribly susceptible to tobacco and nicotine and their viruses.

When you purchase tomatoes, whether it be transplants or seeds, get the kind with the most virus and disease resistance, the tags will refer to VF and VFN resistance on the name label. These varieties have been developed with natural disease resistance, and it sure does work. In very high humidity, tomatoes can often get the viruses without the natural resistance type.

Do you actively 'de-sucker' your plants? Only do this once or twice at the beginning of the season and then leave them alone. I had a leaf curl problem similar to what you are describing when I would sucker them heavily. The plants would eventually recover.

Here is a great UC Davis website for the pests and diseases of tomatoes:

http://axp.ipm.ucdavis.edu/PMG/selectnewpest.tomatoes.html

Jane writes~
My tomato plants are getting yellow leaves with brown spots. Help!

A. You have a fungus, very common, so do not worry, but you must take care of it pronto or you will not be getting any good fruit!

Sulfur is a fungicide used as a dust or spray to control powdery mildew, brown rot, black spot, and certain other pests, as well as spider mites on tomatoes. It can cause foliage injury if the temperature is over 90 degrees F.

Dark brown irregular spots with target rings and yellow haloes develop on leaves, stems, and fruit; spots on fruit are often at stem end and are sunken: Early blight (fungal disease).

Control: Resistant varieties; use registered fungicide; remove old plant debris; rotate tomatoes with beans or sweet corn.

Phoma rot (fungal disease) is not as common as early blight and you will be safe using blight controls.

Uniformly small (1/8") chocolate brown spots or dark spots with tan centers develop on leaves from bottom of plant to top; spots sometimes form on stems but never on fruits; leaves shrivel: Septoria leaf spot (fungal disease).

Control: Use registered fungicide; remove old plant debris and destroy away from the plants as the fungi spores will spread back onto your tomatoes and other plants.

Bacterial spot:
Not as common as Septoria leaf spot; control for bacterial spot is to use Clorox treated seed and Kocide spray from a nursery.

Small (1/8") chocolate brown spots on leaves and fruit; spots on fruit are raised: Bacterial spot

Use Clorox treated seed; avoid overhead watering; use fixed copper bactericide (e.g., Kocide) if available locally; remove old plant debris; rotate crops.

Assistance from: Arizona Cooperative Extension, College of Agriculture, The University of Arizona.

Q. My tomato flowers were falling off during the first month of blooming. Now they have been setting fruit. Why is that? Was it the rain or food?

A. Blossom drop is usually caused by low night temperatures. If cool temperatures cause you to lose the blooms, the plants will eventually flower again, but your harvest will be delayed.

There are varieties that can withstand cool nights, but they usually produce smaller, less flavorful fruit. If you want to get a head start, try planting some of these cold resistant varieties as an early crop, followed by a main crop of your favorite varieties.

Other possible causes for blossom drop are magnesium deficiency and fungal infection. Epsom salt is a good source of magnesium. Dilute a tablespoon of Epsom salt in a gallon of water, and spray the plants as needed. If you suspect a fungus may be the cause of the problem, spray with a fungicide, available at a local garden center. Follow the directions carefully.

Q. My tomatoes are suffering with a spot at the end of the fruit. What is going wrong?

A. Blossom end rot appears as a large, brown to black soft spot at the bottom of the tomato just as it is beginning to ripen. You cannot save a tomato once it is affected, but picking off all the bad fruit will allow the plant to devote its energy to developing healthy tomatoes. The ruined fruit can be tossed on the compost pile.

Blossom end rot is caused by a calcium deficiency, which is usually the result of an uneven water supply. Tomato plants need a steady supply of water to absorb the necessary calcium from the soil. Uneven rainfall amounts must be supplemented with deep soakings to encourage the plants to send out deep roots that are not as sensitive to brief dry spells as are shallow roots. Mulch around your plants to help the soil retain moisture.

Agricultural lime contains calcium, and in severe cases, working a little lime into the soil may help. A very acid pH will also prevent the plant from absorbing calcium, and lime will help to correct a pH problem. Soil testers are available at most large nurseries.

Ronnie writes~
My father in law wants to start a greenhouse. He was wanting some information or resources on planting tomatoes in a greenhouse. Any help or websites to look at would be helpful.

A. After some searching, I located a good general website with the basic cultural information for growing tomatoes in the greenhouse and outdoors.

"Tomatoes are easy to grow provided you can give them the right conditions and keep them well watered and fed. Supermarket tomatoes will never taste the same again once you've picked fully-ripened fruits off your own plants. In our uncertain summers, growing tomatoes in a greenhouse is the surest way to get a reasonable crop in all parts of the country.

Whether you grow them outdoors or in the greenhouse, tomatoes can suffer from a range of pests and diseases, as well as problems caused by particular growing conditions."

What you will need:

Sowing the Seed
Growing in the Greenhouse
Training
Watering
Feeding
Temperature
Harvesting
Tomato Diseases:
Problems where the whole plant has wilted
Problem with the stem
Problems with the leaves
Recommended Varieties

http://www.which.net/gardeningwhich/advice/tomatoes.html  A wealth of information.

Madeleine writes~
I have these weird dark spots on the tomatoes and it seems to be affecting them. What can I do so I do not lose my whole crop?

A. Early blight is caused by a fungus and is one of the most common tomato diseases. The first symptom is irregular brown spots on the lower leaves, possibly also on stems and/or fruit. On stems, spots are small, dark, and slightly sunken. On fruit, you'll see dark, sunken, leathery lesions near the stem. The greatest damage usually occurs after the fruit sets; leaves fall off and expose the fruit to harmful direct sunlight.

Give plants plentiful air circulation by spacing them at least 24" apart and trim excess foliage, especially lower leaves and branches to allow for cross air flow. Consider blight-resistant cultivars such as 'Mountain Fresh', 'Mountain Supreme', and 'Plum Dandy'. Never watering from overhead. Apply chemical or organic [as Safer's] fungicides, which will control the spread of the disease but will not eliminate it. Remove and destroy infected plants throughout the growing season to prevent spread.

Assistance from Gardening Club

Nancy writes~ I fear I have put too much composted manure in for my tomatoes. Will adding extra P boost blossoming and vegetable production? If not, what can I do? The plants are presently about a foot tall & growing rapidly & beautifully. I want to ensure a good crop.

A. If you applied sterilized decomposed manure about two weeks after planting the tomato plants, you will be fine. Later than that and you have provided excess Nitrogen which encourages foliar growth, not flowering and therefore fruit production. The addition of Phosphorus, like Superphosphate, will assist in balancing the elements in the soil. Fruit production will be delayed no doubt but the season is still ahead, so do not apply any more Nitrogen this year and hope for the best. Make sure that the plants are well-watered, especially during dry periods.

Donna writes~
I have a tomato that is growing in the window sill. No dirt. Just on it's own. What causes this?

A. The seed has landed there and germinated. All it needs is some moisture and light. Its foliage can draw nutrients from the water unlike our ability. Rain water is particularly full of N, P and K plus minor elements needed for growth. Sooner or later the plant will topple over due to lack of root support unless it is staked. Best to transplant it while young into a small pot and then later into a sunny garden area.

Ruth writes~
I planted 4 tomato plants last spring, two plants died but the other two grew huge and healthy. Problem: they produce flowers, but none of them mature to fruit. Can you tell me what the problem could be? There are others in the area having the same problem, nice plants no tomatoes.


Cold nights prevent pollination of the flowers which leads to bearing fruit. Tomatoes are very sensitive to night temperatures. They will flower, but will not begin to pollinate and set fruit until nights approach the high 60s. Gardeners can experience many nights during April and May where temperatures drop into the 40s and 50s. Even though this is not cold enough to seriously harm the stems and leaves, such temperatures result in tiny aborted fruit. On a more positive note, plants have had time to become strong and develop a larger size. This might allow them to set and mature heavier than normal crops later. Be patient and watch for warmer nights to improve the number of tomatoes that appear on your plants. Resist the urge to try to provide a remedy by increasing fertilizer applications. Heavy nitrogen applications during mid to late season can also reduce fruit set.

Tamala writes~
We planted our garden this week, which included tomatoes of course. The plants looked good at planting, hubby watered them good afterwards. I noticed the next night when I watered the garden after the sun was heading down that all the big boy tomato plants look droopy. What have I done and what can I do to fix them? Oh, we used a triple 13 fertilizer at planting.

A. The use of the fertilizer right at planting may have damaged the tender roots but will not cause death of the young plants. Keep the plants on the dry side as there are less healthy roots to absorb the water around the root ball. If the days become intense and bright, cover lightly with upturned pots or a couple layers of newspaper to keep the strong sun rays from stressing the plants further. The tomatoes should make new roots rapidly and the wilting will end. Do not reapply fertilizer for a while and when you do, use 1/2 recommended strength for one month. In the future, it is best not to feed any new young plants for several weeks while they adjust to the new environment. The existing soil will have plenty of food for them.