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The Seed Program
Growing Hints

This is one of the many growing hints that are available as a bonus with a registered copy of The Seed Program.


(Bonus: The growing hints for tomatoes were previously only available to registered users of The Seed Program.)

Tomatoes are easily the most popular of all crops with home gardeners. They are not the easiest to grow, but few plants offer such a drastic contrast in quality between store bought fruit and home grown. This is partly because the supermarket fare is generally picked green and ripened artificially before sale, and partly because the types of tomatoes grown for the commercial market are chosen for tough skins and keeping quality (to hold up to mechanical harvesting, packing and long shipment times) rather than taste. The home gardener can grow a far superior tomato by allowing the fruit to ripen on the vine before harvesting, and an even more delicious crop by growing some of the old time (so-called "heirloom") tomatoes that were developed back when taste was the most important thing.

Tomatoes are warm weather plants and require a long growing season. It is necessary to start the plants from seed indoors in late winter or early spring. Any garden center will have a selection of plants for sale in the spring, but for the widest choice of varieties you will have to start your own. Plant the seed in plastic cell packs ("6 packs") or plastic pots and keep them warm and moist until the seed germinates. Place them directly under bright light as soon as the seedling emerges, or sooner. Insufficient light is a common problem with plants grown from seed. Without plenty of light the yound plants will become "leggy" -- long and thin with weak stems and increased succeptibility to disease.

It is important to keep the plant gowing strongly and steadily to insure the earliest and biggest harvest. Avoid leaving a large tomato plant for too long in a cramped container. If the height of the plant is more than two times the depth of the planter or if roots start to emerge from the bottom of the planter, it is time to move the plant to bigger quarters. The plant may need to be transplanted two or three times if you have started it early. Go for height, rather than width, when choosing containers. Tall plastic or styrofoam cups are good for larger plants, or even a half gallon milk carton with the top removed and drainage holes punched in the bottom. The tomato is one of the few plants that have the ability to grow new roots from the burried stem, so plant them as deeply as possible when transplanting. Remove the lower leaves, if necessary, and cover the lower stem with soil. The increased root system will promote a stronger, healthier plant.

Tomato plants will not grow much if temperatures are cool, so don't rush them out into the garden too soon in the spring. Well after the first frost, harden the plants off by leaving them outside a bit longer each day. You may burry the stem when planting them outside also, to increase the root system. Be sure to place a paper or cardboard cut worm collar around the stem, about two inches above and below the soil line. Young tomato plants are often destroyed by cut worms when they are first planted in the garden.

If the weather is still somewhat cool, the plants may benefit from some sort of protection when first transplanted. One of the best is the "Wall-O-Water," a cylinder of plastic tubes that are filled with water and protect the plant from temperature extremes and even a mild frost if the top is closed. It is usually necessary to support Wall-O-Waters with a few wooden stakes, like a teepee, so that they don't collapse and crush the plants. Other plant protectors can take the form of wire cages covered with plastic, plastic milk jugs with the bottoms cut off, or surrounding the young plant with intact plastic jugs filled with water. The tomato is still a tropical plant, and none of these methods will do much for a plant theat is planted too soon in the spring. A serious frost will kill the plant, so its best not to take chances, especially if you have a limited number of plants that have been painstakingly grown from seed. But these "mini-greenhouses" are good for an early boost for the young plants, and by protecting the young plants from the sun and the wind they will also help to reduce transplant shock if the plants have not been fully hardened off.

There are two basic types of tomatos: determinate and indeterminate. Determinate tomatos will reach a specific size or height and then stop growing. They sometimes produce earlier in the season, but usually don't continue producing fruit all season. Determinate tomatos do not need as much support (tall stakes or trellises) and pruning as indeterminate tomatos. Indeterminate tomatos will keep growing indefinitely, and if left to sprawl will reach enormous lengths. They benefit from some pruning and require tall stakes or trellises. Indeterminate plants usually bear ripe fruit slightly later in the season, and generally continue to produce fruit until the plant is killed by frost.

It is generally agreed that some sort of trellising is best when growing tomatos, but there is no agreement on the best procedure to use. There are many different options. One of the most popular is to place a stake next to each plant and keep the growing plant pruned and tied to the stake as it grows. The pruning is essential if using a stake. At each new branch on the plant, a sprout will grow in the middle of the "V" formed by the main stem and the branch. This small sprout, called a "sucker," can be snipped off as soon as it appears or it can be allowed to develop a few leaves, but the end should then be snipped off to prevent it from forming a whole new main stem. A tall stake is best, and most tomatos (indeterminate tomatos) will grow to the top of the stake by early or mid- season, and the top of the plant should be snipped off at this point. This will force the plant to concentrate its energy into developing side growth and ripening fruit. Pruning is generally felt to produce an earlier crop and allow plants to be grown closer together (a foot and a half or two feet instead of three), but may slightly reduce the total yield per plant and worsen the chances of the fruit being damaged by "sunscald," because pruned and staked plants do not have as much leafy cover for the fruit as unpruned plants.

If space is tight, two tomato plants can be planted on either side of a stake -- the yield per plant will be reduced, but the yield per square foot will increase. Rough wooden stakes are most popular, but metal or bamboo can also be used and have the advantage of offering repeated use without rotting. No matter what material is used for the stakes, the plants will need to be checked every few days and tied in place (and pruned). They will not wrap around a stake like some other vines. Another variation is to use three or four stakes in a block and tie them together at the top to make a tomato teepee. The forms a strong support and the stakes do not have to be burried as deeply in the soil.

Another popular method is to use "tomato cages" -- wire cylinders that are placed over small plants which are allowed to grow up through the center and are not pruned. The best material to use is concrete reinforcing wire that is made up of six inch squares and is about five feet in height. This is strong enough to last many seasons, and the wide holes allow enough room to reach in and harvest all but the largest tomatos. Cut sections about five feet long and leave the wire sticking out long on one end. You will need a pair of long handled bolt cutters to cut this material. Curl it into a cylinder and bend around the long edges left from the first cut to hold the shape. Then (or before bending) remove the very bottom cross piece, leaving six inch lengths of wire that can be pressed down into the soil. If strong winds might be a problem at some point during the growing season, you will probably want to tie the cages securely to a stake to prevent them from blowing over.

Tomatos can also be planted next to a piece of fencing and wound through it or tied to it as the plant grows. Some pruning will probably be necessary if fencing is used, and the taller the trellis, the better. Another method is to place stakes only between every three or four plants, and winding strong string or baling twine between the stakes and the plants as they grow. Some pruning is also helpful if this procedure is used, or the whole area can easily become a jungle of tomato vines. Follow the same pruning procedure of removing suckers for a few weeks to prevent the low branches on the plants that would get in the way and leave fruit too close to the ground and likely to rot.

Conventional wisdom holds that tomatos should not be mulched until the ground has thoroughly warmed in the spring, but I have good results putting down a thick mulch of leaves as soon as the plants are put in the ground, or even the autumn before. The cool soil may delay the first fruit slightly, but this is more than made up for by the elimination of weeds, no need for cultivation, steady moisture in the soil and the protection that the mulch offers to any fruit on low branches that may be resting too close to the ground. I think that the incidence of disease is also reduced by the mulch, since many disease organisms live in the soil and infect the plant when rain splashes soil up onto the leaves.

Tomatos are, unfortunately, subject to a number of insect pests and diseases. Tomato hornworms are one of the most common insect pests. These large caterpillars are light green and have a redish "horn" projecting from one end. It is usually possible to hand pick them, although their color can make them hard to spot against tomato foliage. Watch for leaves that have been chewed down to the stem. Pruning tomato plants will make it easier to spot these pests. When you find them, crush them with your shoe or drop them in a can of soapy water to drown. If you find any that have white eggs attached to their backs, leave them alone. These are the eggs of a parasitic wasp. The larvae of the wasp will soon emerge and feed on the caterpillar (killing it) and will grow into a new generation of wasps that will help to rid your garden of horn worms in the future. BT, the safe organic insecticide, can also be used against horn worms, but it has to be sprayed frequently and is most effective on the small caterpillars that have only recently hatched.

Colorado potato beetles will sometimes infest tomato plants, but will usually prefer your potatoes, if you are growing any. Hand pick the adult beetles and any larvae, and crush any of the brick red eggs that you find on the undersides of leaves.

Aphids will sometimes attack tomatos, especially young plants. Check the undersides of leaves for these tiny insects. If you avoid using pesticides in your garden, you will usually have enough beneficial insects (such as lady bugs and lacewings) around to prevent the aphid population from getting too large. If the aphids seem out of hand, blast the plants with a strong blast of water from a hose to rinse them off, or spray the plants with insecticidal soap. Be sure to get the undersides of the leaves.

Tomato diseases include early blight, late blight, curly top verticillium wilt and fusarium wilt. Disease symptoms vary, but watch out for stunted plants, leaves that have a wrinkled blotchy appearance or leaves with spots. with all diseases, prevention is the best approach. Be sure to rotate your crops -- do not plant tomatos where tomatos or related plants such as peppers, potatoes or eggplants (the nightshade family) have grown during the past few years. Give seedlings and mature plants plenty of room for good air circulation, especially where conditions are humid. The unwitting gardener will often unintentionally spread disease from one plant to another. Avoid handling plants unnecessarily, and keep away from the plants altogether if they are wet, as disease spreads more easily when the plants are wet from rain or dew. If you see an individual plant that has likely become diseased, remove it from the garden (burn it or throw it out with the trash) and wash your hands and clean any tools that might have come in contact with it before handling healthy plants.

Tobacco mosaic virus is a disease that can infect tomatos and other members of the nightshade family. It causes stunted growth, wrinkled leaves, yellowish mottled leaves and increased susceptibility to other diseases. Smokers should wash their hands before handling tomato plants, as this disease can spread from tobacco (another nightshade). A gardener handling different plants or even brushing against different plants can transmit mosaic virus from one plant to another.

Some tomato varieties offer disease resistance, usually indicated by the letters VFN in seed catalogs (for resistance to verticillium wilt, fusarium wilt and nematodes, respectively). These varieties are useful to home gardeners, especially if disease has been a propblem in the past, but one should remember that these varieties only offer resistance, not immunity. Good growing procedures should still be followed to minimize the incidence and effects of disease. Don't let a lack of disease resistance dissuade you from trying some of the great old hierloom varieties, for many are well worth a try. And don't let the long list of diseases discourage you from growing tomatos. They are robust plants and generally produce in abundance even if attention to disease risks is rather lax.

Blossom end rot is not a disease but a physical disorder of tomatos that causes a dark rotten spot to appear on the side of the fruit opposite to where it is attached to the stem. The rot usually appears while the fruit is still green and increases in size as the fruit grows and ripens. Nothing can be done for an affected fruit, so they should be removed to allow the plant to focus its energy on unaffected fruit. Blossom end rot is caused by a calcium deficiency, but this lack of available calcium is usually caused by uneven moisture -- usually soil that has dried out to much, although poorly drained, soggy soil can sometimes cause the same symptom. A good thick mulch is often all that is needed to keep the soil moisture steady and prevent the excessive drying that usually causes blossom end rot. It is also a good idea to have your soil's pH tested, and add lime if the soil is too acidic (below 6 on the pH scale).

A mulch will also help to prevent fruit from cracking. This usually occurs if a long period of very dry weather is followed by a great deal of rain. The sudden increase in moisture will cause the ripening fruit to swell, sometimes to the point that the skin will develop cracks. A thick mulch will help to prevent this by keeping soil moisture levels more constant. Irrigation during dry weather will also help, but drip hoses are preferable to overhead watering in order to prevent the appearance of disease.

Sunscald is another problem that may be brought on by hot, dry weather. A green tomato exposed to too much direct sunlight may develop a white or yellow patch that persists as the fruit rippens and often begins to rot later on. The problem is more common in arid regions like the Southwest and is much more likely to appear on plants that have been weakened by disease and lost some of their leaves. Excessive pruning will also leave fruit more vulnerable. If leaf cover is insufficient, the fruit can sometimes be protected from sunscald by using a paper bag or a piece of row cover to shade it.

In spite of all the problems that can occur when growing tomatos, they are an exciting crop that is well worth the effort. This is partly because of the tremendous variety of tomatos available. Seed savers have preserved literally hundreds, even thousands of different varieties, and new ones are being introduced by plant breeders every year. Ripe fruit are not just red, but may be yellow, orange, white, black, green, pink or striped combinations of these colors. There are tomatos that are ribbed like pumpkins. There are stuffing tomatos that are hollow like peppers. Tomatos come in every size from tiny, berry like peppers a quarter inch across to huge grapefruit sized giants.

Most of this diverse assortment of tomatos will not be found in commercial seed catalogs. Most varieties are preserved by home gardeners just like you. Tomatos do not readily cross pollinate, so seed can be saved from any open pollinated (non-hybrid) tomato and grown to produce a plant that you can be reasonably sure will produce fruit much like the seed came from. Saving seed from tomatos is a simple process. The best procedure is to scrape or squeeze the seeds from a fully ripe tomato into a glass jar, add a little water and set it aside to ferment for a few days. Stir the mixture once or twice a day. It won't smell very good, but that is natural. This fermentation period will break down the jelly-like mass that surrounds the tomato seed and kill off some of the disease organisms that may linger on the seed and later affect the plant grown from it. After two or three days a layer of mold will probably appear on the surface, but this does no harm. About this time you should be able to see that most of the seed has settled out to the bottom. At this point, dump the seed in a large shallow bowl, fill it with water and stir. Wait a few second for most of the seeds to settle to the bottom and dump the water off the top. Fill the bowl with water again and repeat this rinsing procedure three or four times and you will be left with clean seed. The lighter seed that floats and is poured off with the pulp probably wouldn't germinate anyway. When the seed is clean, pour off as much water as possible and then spread the seed to dry on paper towels on a tray. When the seed is thoroughly dry, pack it away in glass jars or paper envelopes.

It is best to save seed from the best growing plants, not the best fruit. All of the seed from all the fruit on a single plant, large or small, is basically the same genetically, but by saving seed from superior plants you are selecting superior seed for a better crop next season. Make careful not of the variety you are working with when you harvest the fruit, and label the jars, the paper they are drying on and the container they are later stored in. All that remains is too share the seed of your favorite tomatos with other gardeners -- usually getting some seed for a new variety in return. Most dedicated tomato growers will try a few new varieties every year. It's one of those things that makes gardening interesting, and different every season.

For more crops, more complete gardening information, a garden journal and a planting schedule you can customize for your region, purchase The Seed Program!

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