No doubt some of you have already rushed the season, but for the rest of us, the traditional time to plant tomatoes is around Mother's Day. With all the rain we have had, this weekend could provide the perfect opportunity, except that the temperature is going to drop on Sunday night. While not desirable, the brief bout of cold probably won't hurt the plants much, if you go ahead and plant today or tomorrow.
First, select a site that receives at least 8 hours of sun every day. Shelter from the prevailing wind is desirable, as staked or caged tomato plants are subject to wind damage. Soil should be amended with organic matter, well-drained, and not extremely rich. Too much nitrogen at the wrong time can reduce productivity. Add a quart of well-composted cow manure to each planting hole at transplant time, or side dress the plants with a commercial organic fertilizer at the rate recommended on the package. Stop fertilizing when blooms appear, however, or you will reduce yield.
Select healthy, stocky plants for transplanting. (Note: You can also start tomato plants from seed between now and July 15 for a fall crop.) To improve the lot of leggy plants, or just to ensure that any plant produces a good root system, strip off all but the top three or four pairs of leaves and bury the stems up to the lowermost remaining pair. Water the soil around the plants well after transplanting, avoiding getting the leaves wet. Wait until the soil warms up thoroughly, then apply a deep mulch of straw, leaves or pine needles around the base of the plants. Mulch helps keep the soil evenly moist, an important factor in tomato production. Covering the soil also prevents splashing dirt on the leaves, often a source of fungal diseases.
Use cages or stakes to support growing tomatoes. Even the smaller, determinate varieties do best if staked, because they grow luxuriantly in Tennessee's warm, humid summers. Use soft string, strips of panty hose or another soft material to secure the stems to the support. Don't tie them too tight, or you risk garroting the stem.
Pests and diseases attack tomatoes, but your best defense is to provide good growing conditions and the plants will usually take care of themselves. Many fungal diseases can be avoiding by growing resistant varieties, such as Celebrity, Big Boy, Better Boy, and Rutgers. Resistant types have the letters "V," "F," or "N" or some combination of these after the name on the label. The letters indicate resistance to verticillium, fusarium, and nematodes, all important tomato scourges. Tomato hornworm and fruitworm caterpillars can be controlled with Bt sprays. I have found neem oil helpful in deterring squash bugs, which sometimes move into the tomato patch and damage fruits with impunity.
Depending upon the variety, you can expect your first tomato crop around the Fourth of July, just in time for slicing on hamburgers.