The Tomato Challenge
If you have had little success with tomatoes don’t take it personally. Tomatoes are tough to grow in the coastal south. Summer heat causes problems with ripening, fruit set, and flavor, yet allows diseases and pests to thrive. While we can’t change the weather, there are some things that can be done at planting time to increase your chances of success.
Tomatoes grow and produce best when daytime temperatures range from 70 to 80 degrees, and night temperatures fall between 60 to 70 degrees. Most of our summer days far exceed these spring like temperatures, causing plants to shed their blossoms without setting fruit. Fruits that do ripen when high’s reach into the mid 90’s have less flavor, ripen unevenly, and often develop hard white areas inside their flesh. Planting tomatoes as early as possible will give plants more time to grow and produce under ideal temperatures before the hottest part of summer.
Mid to late April are the best time to plant tomatoes in Onslow County. Keep in mind light frosts are a possibility through the end of April, so be prepared to protect plants if temperatures in the 30’s are predicted. Covering plants with an old sheet or specially made row covers will protect them down to 30 degrees. Make sure covers extend fully to the ground and are well anchored.
Tomatoes are one of the few vegetables that have the ability to produce roots along their stem. Because of this, setting the root ball two or three inches deeper than soil level at planting time will result in plants with larger, more extensive root systems. If you have plants with long leggy stems do not bury the roots several inches deep. Instead, dig a shallow trench and plant them lying sideways, so the leggy part of the stem is planted horizontally two to three inches below soil level. Allow the top six to ten inches of the plant to stick up out of the soil. You can make a mound of soil at the end of the trench to help the top part of the plant tilt upward, but don’t worry if it is not perfectly vertical to start with. The sun will draw the plants upright within a few days.
Tomatoes grow best in deep, rich soils so be sure to amend your garden with compost before planting. Space tomato plants at least three feet apart and place a cage around plants to support them as they grow. Mulching the soil under and around tomatoes will help keep soil moisture even and prevent soil temperatures from getting too hot.
Plant Several Varieties
There are a plethora of different varieties of tomatoes available, including heirlooms, cherry tomatoes, and the typical round red types. There is no one, best variety to grow in our area. Cherry tomatoes are the easiest to grow and every garden should include at least a few of these highly productive plants. Many people love the flavor of heirlooms but not all heirlooms produce well in our summer heat. If you would like to try heirlooms look for ‘German Johnson’ or ‘Homestead’, both of which produce well in the south.
Of the modern round large fruited tomato types ‘Celebrity’ and ‘Better Boy’ are favorites for the south. Both produce medium to large size fruits and are resistant to fusarium and nematodes, two common soil dwelling diseases that attack tomato roots. For even more disease resistance include a couple of varieties that are resistant to tomato spotted wilt virus, such as ‘Southern Star’, ‘Amelia’, or ‘Crista’. Planting disease resistant varieties will increase you chance of success, but keep in mind no one tomato variety is resistant to all, or even most, of the diseases that commonly plague this popular crop.
If you have room, plant tomatoes in several different spots around your yard, rather than all together in one bed. Avoid planting tomatoes in the same location year after year since this allows diseases to build up. If you have had problems with tomato wilt diseases in the past, consider potting plants in large containers filled with potting soil. Whether you plant in containers or garden beds, be sure to apply a slow release fertilizer when you plant. Slow release fertilizers include organic fertilizers like Plant Tone as well as time release products like Osmocote. Supplementing plants with liquid fertilizers like compost tea or Miracle Gro for the first few weeks after planting will help them establish quickly, but there is not need to liquid feed plants all season. In fact, over fertilizing reduces fruit set and encourages problems like blossom end rot.