Tomatoes are a popular garden plant that grows well in Oklahoma when given the proper amount of water and fertilizer during the summer growing months. Plant tomato seedlings that are six to eight inches in height with stocky stems in a soil that holds moisture yet is well-draining to prevent standing water. Choose tomato varieties that are disease resistant to Fusarium wilt and nematodes, as these are common problems in Oklahoma. Three tomato plants per family member will provide an adequate amount of fresh tomatoes during harvest.
Select a planting location for tomatoes that has a well-draining, fertile soil and full sunlight. Tomatoes do not grow well in a heavy, clay soil.
Prepare the planting area by working two to three inches of organic compost into the soil with a tiller to a dept of six to eight inches. Test the soil pH to verify it is approximately 6.5. Work ground rock sulfur into the soil to lower the pH number and let it rest for two weeks before planting.
Plant the tomato seedlings once the soil temperature has reached 60 degrees F. Oklahoma soil reaches this temperature in early April. Dig a hole that is slightly deeper and two to three times wider than the container the seedling came in.
Set the seedling into the hole so the root ball and stem are lying in the hole and approximately six inches of plant is above the ground. This allows the plant to develop a strong root system. Space the plants two feet apart in rows that are three feet apart.
Water the seedlings immediately after planting and apply a water soluble tomato starter. Continue to water the plants during the growing season to keep the soil evenly moist. Tomato plants require weekly water applications of at least one inch deep during the spring months and two inches during the hot summer months. Do not allow the soil to dry out completely as this will hinder plant growth.
Fertilize the tomato plants with a 33-0-0 fertilizer at a rate of three pounds for each 100 square feet once the tomato fruit has grown to one-third the mature size. Small gardens should fertilize at a rate of 2 tablespoons for each plant. Work the fertilizer in the soil around the plants as a side dressing and water the area well after applying fertilizer to promote absorption. Apply a second dose of fertilizer two weeks after the fruit begins to ripen. Apply a third application one month following the second.
Apply a grass clipping or organic matter mulch around the plants to retain moisture and limit weed growth that competes with the plants nutrients and water.