How and where you plant tomatoes is an important first step for a bountiful harvest. Deep, loamy, well-drained soils are best for tomatoes. As with most garden vegetables, tomatoes prefer a slightly acid soil with a pH of 6.2 to 6.8. I also recommend a soil test if one has not been taken in 4 or 5 years.
Tomatoes need at least 6 hours of direct sun daily for highest yields. When choosing a site, it s also important to select an area where tomatoes and other solanaceous crops (potatoes, peppers, and eggplants) have not been grown for 2 to 3 years. Solanaceous crops are susceptible to many of the same diseases. Crop rotation should help reduce disease problems.
It is a little late to start tomatoes from seed. Typically, you need to start them 5 to 6 weeks before the intended outdoor planting date. In central Iowa, May 5-10 is the suggested outdoor planting date. Gardeners in southern Iowa can plant a week earlier, whereas those in northern Iowa should wait an extra week.
When purchasing tomato plants, select stocky, dark green plants that do not have fruits. It may be important for you to have the first tomatoes on the block, but fruits stunt plant growth and reduce the total yield.
Harden or acclimate the tomato plants outdoors for a few days before planting. Initially, place the plants in a shady location and then gradually expose them to longer periods of direct sunlight. After 5 to 7 days, the tomatoes should be ready to be planted in the garden. Set plants deeply into the soil burying them up to their first set of true leaves. For tall spindly plants, pinch off the bottom leaves and lay them sideways in as trench. Carefully bend the stem upward so that the upper few inches of stem are above the soil surface. Roots will develop along the buried stem.
Because tomatoes take some time to develop, the last practical date for planting is approximately June 20. For more information, please stop by your local county extension office and pick up publication PM 608, Tomatoes .
This article originally appeared in the 5/2/2003 issue.