   Growing Tomatoes - May 17, 2000 Jeff Schalau, County Director, Agent, Agriculture & Natural Resources Arizona Cooperative Extension, Yavapai County What event do most backyard vegetable gardeners anticipate most during the summer growing season? The day they harvest their first, succulent, vine-ripened tomato. Most of us don't care how much money we spend in this pursuit. That's not the point. The objective is simply to grow the world's best tomatoes on our own. For most of us, the first tomato that forms on the vine is monitored daily, coveted and revered as it gets larger. This ritual goes on until the fruit is optimally colored and has that perfect balance of firmness and softness. By definition, this fruit will be better than any other tomato available on the planet. This week's column is designed to ensure the highest level of success in this summer rite. Tomatoes are easily grown from seed, but it is much too late to start plants from seed this year. Nurseries carry plants of the most common varieties. However, if you plan to grow obscure or heirloom varieties, you will need to plan ahead and grow them from seed next year. Most of the commonly available, nursery grown varieties have capital letter on the label. These may look something like "VFFNTA". The letters refer to their resistance to common tomato diseases. V stands for verticillium wilt, F for fusarium (multiple F's stand for variety a and b). N for nematodes, T for tobacco mosaic virus, and A for alternaria stem rot canker. Tomato varieties are either determinate of indeterminate. Determinate varieties reach a certain size the stop growing foliage and start producing fruit. Indeterminate varieties grow a bit, set some fruit, grow some more, set more fruit, etc. until the plant dies. Heirloom/open pollinated varieties are those that have been passed down for generations with an excellent taste and more open spaces in the fruit. Hybrid tomato varieties are those with disease resistance, uniform growth and fruiting characteristics, and may have less intense tomato flavor than the heirloom types. Terry Mikel, Cooperative Extension Horticulturist, is a connoisseur of vegetable varieties. His favorite tomato variety is "Celebrity": a VFFNTA hybrid. When planting tomato plants, be sure to add ample nutrients and organic matter to the soil. Complete fertilizers with high phosphorus are best (i.e. 5-10-8 or similar type). Add two pounds of 5-10-8 per 100 foot row or 10 by 10 foot area. For those unfamiliar with fertilizers, the three numbers stand for percent nitrogen-phosphorus-potassium. Phosphorus promotes root growth, flowering, fruiting. Whereas, too much nitrogen will cause excessive foliar growth and limit potential for fruit production. Individual tomato plants should be planted at least 24 inches apart. After preparing the soil, place plants deep into the soil. Some people dig an extra deep hole to plant in, then allow the plant to grow upward out of the hole and backfill soil around the stem. This promotes a greater root mass and stronger stem. The same technique can be applied to plants with elongated stems. In this case, the stem is buried in a horizontal trench at planting time. To stake or not to stake. Some folks (like me) prefer to tinker with their garden and manipulate tomato plants by staking them or using cages. Others allow the plants to sprawl every which way across the soil surface. It really doesn't matter which you do, fruit production will be roughly the same either way. On the ground, you may lose some fruit to rot and insect damage. Staking can save space but will also expose the plant to wind and sap some energy to support the vines. Pollination occurs with the assistance of bees and other flying insects. However, the pollen does not need to be transferred from flower to flower. Rather, it is the vibration of the beating wings as the insect is in contact with the flower that transfers the pollen from stamen to stigma. Insects can do this for you under normal conditions. If growing in a greenhouse, keep in mind that insect pollinators will need access. Pollination can also be accomplished through mechanical means. Terry Mikel recommends using an old electric toothbrush motor and removing the brush portion. Lightly touch the vibrating portion of the motor on each flower to pollinate. This is most effective when wearing a yellow and black striped suit. When temperatures rise above 90 degrees F, tomatoes decline in fruit production. Choosing a site where temperatures are moderate may help overcome this tendency. Tomatoes also have many pests: too many to list them all here. In brief, watch for tomato horn worms, hand pick them, and squash them. Chickens also love to eat them. Curly top virus can also be a problem in our area. The only remedy for curly top virus is to pull the plant and discard. Splitting of fruit is caused by erratic or excessive watering. For diagnosis of other problems, contact the Cooperative Extension office (see below). At the end of the growing season, pick all green tomatoes before the first killing frost. These will ripen indoors when stored in a cool moist place. Happy tomato growing! The University of Arizona Cooperative Extension has publications and information on vegetable cultural practices and diseases. The Yavapai County Cooperative Extension web site can be accessed at http://ag.arizona.edu/yavapai/. If you have other gardening questions, call the Master Gardener line in the Cottonwood office at 646-9113 or E-mail us at mgardener@kachina.net and be sure to include your address and phone number. |