Tips & Techniques for Growing Tomatoes


 Growing Tomatoes
 Early Blight
Tomato Hornworm
Hornworm with Wasp Pupal Cases
Varieties of Tomatoes
There are many varieties of tomatoes available from the various seed catalogs.  They come in several different shapes and colors with different characteristics.  Red tomatoes are the most common but there are yellow varieties and even purple and green ones.  You can find a striped tomato or a yellow one with less acid.  Most varieties are round, plum or pear shaped.  Sizes vary from around 2 pounds to very small.  Beefsteak tomatoes and varieties derived from them tend to be on the large side.  Cherry tomatoes are on the small side with paste tomatoes falling in the middle.  Vines can be short and sturdy or tall requiring support.  The time required to produce fruit can vary as well.  Varieties can be determinate or indeterminate. Indeterminate tomatoes continue to set and ripen fruit all season long.  Tomatoes can be open pollinated or hybridHeirloom varieties are open pollinated varieties with a known source of origin.  Seeds saved from open pollinated varieties, including heirlooms, should germinate to produce new plants similar to their parents.  Heirloom varieties may have better flavor but sometimes produce less fruit than the hybrids.  One of my favorites is the Mortgage Lifter indeterminate heirloom which produces a lot of tomatoes all season long with good size and flavor.  Hybrids are developed by cross breeding to improve selected characteristics.  As a result, they may be heavy producers, disease resistant, require less time to produce, etc.  You can save seeds from hybrids but they will not necessarily have the same characteristics as the hybrid.  Usually, I plant a few Early Girl hybrid tomatoes to get some to eat early in the season.
Preparing the Soil
It is possible to plant a garden without tilling the soil.  However, a well tilled garden makes planting easier, aerates the soil and provides initial weed control.  I use a large rear-tined tiller for the initial plowing of the garden and the first pass through the middles.  Once the plants are larger, I switch to using a small front-tined tiller similar to the Mantis which can work the middles without much damage to the plants.  There are several techniques for creating straight rows.  One simple and easy way is to mark off rows is using a string as long as the desired rows with a stick tied to each end of the string.  If you cut the sticks the desired row width, they can be used to measure the location of the next row.   Stretch the string where you want to mark off a row and push the sticks into the ground.  Using a hoe, you can make a straight shallow trench beneath the string to guide you in planting later.   Tomatoes like soil that is rich with organic matter.  Digging holes along the trench and mixing in compost or manure will provide the desired soil mixture.  You may also include about a table spoon full of regular commercial fertilizer, e.g. 12-12-12 garden fertilizer, and a lesser amount of Epsom Salt. Don't use too much fertilizer or you will get mostly plants and few tomatoes. The magnesium in Epsom Salt is believed to aid in photosynthesis and in the formation of fruits.
Planting Tomatoes
Setting out tomato plants works better than planting seed directly in the garden.  This is especially true in the northern states where the growing season is shorter.  You can buy plants or grow your own.  The latter costs less and gives you more control over the type of tomatoes grown.  You can buy seed from the various seed companies or save your own from the previous year's crop. Buying seeds provides a greater choose of varieties and allows you to avoid some bad seed problems. Keep in mind that unlike heirloom tomatoes, the seeds saved from hybrid tomatoes will not produce the exact same type of tomato as the hybrid variety.  Tomato plants can be grown in a green house, hot bed or in the house on a stand using plastic trays and grow lamps.  You should start them about 6 weeks before planting time.  The full spectrum grow lights work better than plain florescent lamps.
When planting tomato plants, don't be afraid of placing too much of the plant stem in the ground.  A little extra stem in the soil provides a better root structure. Plants should be spaced about 15 inches to 2 feet apart to allow the plants to bush out and get adequate sun.
Weeding & Plant Maintenance
To minimize the amount of tilling and hoeing required to control weeds, you may want to make all of your middles slightly wider than your tiller.  In that way you can till once down each middle, close to the plants and leave only weeds that come up in the actual row.  Most of the weeds in a tomato row can be removed by hoeing but a few next to the plants will have to be pulled.  You will need to till and hoe about three times before the plants get too large to allow a tiller to go down the middle.  
It is best to provide support for tomato plants.  This can be done by using wire tomato cages or stakes.  If you are planting a lot of tomatoes, sticks cut from brush will serve quite well and is economical.  If you use sticks for support, cut short pieces of string and tie up the plants several times as the plants grow.  Plants grown in tomato cages will need to be rearranged within the cage from time to time.  Pruning the bottom branches will cause the plants to grow tall and be less bushy.
Controlling Diseases and Insects
Tomatoes are easy to grow without too many problems with diseases and pests. However, tomato plants are susceptible to several diseases including blight, leaf spot, and mold. The most severe is the early blight caused by the alternaria solani fungus.  The leaves wither, die and fall off, killing the plants prematurely.  The blight infects the lower leaves of a plant and spreads upward.  The fungus spores are able to survive in infected plant debris in the soil for a couple of years.  Plants infected by the blight, produce smaller and fewer tomatoes which may show signs of sun scald and rot.  Production stops early in the season.
Blight seems to be worse when the weather stays cool and wet for a long time. There are several things that can be done to control the blight.  You can buy disease resistant variety seeds and grow your own plants; rotate your crops to avoid repeatedly planting tomatoes in the same location; remove infected plant material from the garden; provide supports and mulch to keep the foliage off the ground; and use fungicides.  The fungicide selected should be one recommended for this specific fungal disease. 
The tomato hornworm will eat both the tomato plants and fruits.  These caterpillars get large and can devour a lot of material in a short time.  They have a horn on one end and appear dangerous.  They say that they can’t sting but I’m not so sure.  They are not easy to see since they are the same color as the plants. If you see where leaves have been eaten and/or there are holes in the green tomatoes, you need to look for a worm.  To confirm that a worm is there; look for black droppings under the plant.  If you see them, a worm is most likely somewhere on the plant.  Remove it before it can do more damage.
Tomato hornworms are controlled somewhat by parasitic wasps.  Late in the season, you may see hornworms with white pupal cases on their back.  These are not hornworm eggs.  They belong to the brachonid wasps.  Don’t kill these hornworms since they are no longer feeding on the tomato plants. Instead, leave the worms in place so the wasps will hatch to attack other hornworms.  If the remaining worm population is small, you should be able to control them by hand picking worms from the plants.  Should the use of chemicals be necessary, a general purpose garden pesticide will not work as well as an insecticide that targets hornworms.  The insects targeted by a product should be listed on the label.  Always read and follow the directions on the containers when applying chemicals on garden plants.  For specific details on controlling diseases and pests, click on the "Gardening Resources" tab and go to the Sources of Information on Vegetable Garden Diseases and Pests.
Tomatoes ripen starting around August and may continue until the first frost.  It is best to pick tomatoes as soon as the color indicates that they are ready.  Their bright color attracts birds and animals that would otherwise eat them.  Removing the steams and placing them in a basket or sturdy box is better for transporting to minimize damage.  If you keep damaged tomatoes, they should be kept separated from the others.  You don’t want to stack tomatoes too high causing excessive pressure on the bottom layer.  Store them in a cool place and check periodically for any signs of rot.  A rotten tomato can cause others touching it to rot.  Tomatoes can be frozen or canned to keep for long periods of time.