CLEMSON, S.C. — I hope and think we have had the last weather tantrum (cold snap) of the year. I am sure many folks thought I was crazy or too careful when I advised to wait until now to plant the garden. Most years it seems winter has to have “A last Hoorah” just to keep us inline. So now let’s get down to serious gardening and talk about everyone’s favorite “Home Grown Tomatoes.”
First of all, know your garden soil or much easier plant them in some type of sterile container using a soil-less (potting soil) mix. Most soil-less mixes are pH adjusted so let’s talk about the more difficult garden soil. The pH needs to be close to 6.5 but not over about 6.8. You know this by taking a soil sample which should have been done earlier but still can be done now and the amount of dolomitic lime recommended can be applied on over the top of the plants and lightly tilled into the ground trying not to damage the roots. Even though it will be fall before the lime has fully done its job and properly changed the pH, it is better to apply when it is needed. The lime will add calcium helping with blossom-end rot but in addition to the lime I always till in some gypsum also called land plaster at 2 lbs. per 100 sq. ft. to add extra calcium. As the tomato plants are planted and continue to grow keeping the soil moist but not wet will also help with blossom-end rot. Check this by picking-up a handful of soil and pressing together in your fist and release, if it readily falls apart it is time to irrigate. The best way to keep the soil moist is to apply a mulch. Personally, I like putting down 6 – 8 sheets of newspaper and then applying a 3 to 4 inch layer of an organic mulch. The fertility of the soil is also very important in tomato growing and the best way to manage most nutrients is a soil sample. However, a soil sample will not tell you anything about how much nitrogen is available in the soil, but it will give you a recommendation on how much fertilizer including nitrogen to add to the soil. The proper amount of nitrogen fertilizer is one of the secrets of tomato growing where most homeowners fail. Many folks brag about their 10 ft. tall tomato, but when I ask about the quantity of fruit they cower. Growth and fruiting has to be balanced. You want as much fruit as possible but you need to get large enough of a plant to protect the fruit from sunscald. I accomplish this by just putting enough nitrogen to the plant to get a plant about 18 inches tall as the plant runs out of nitrogen it will slow growth allowing fruit set to begin. Once the plant has got some fruit as large as a quarter the plant has switched from a growing to a fruiting stage. The plant will continue fruiting as I add more nitrogen to grow a bigger plant to protect the fruit. This is what I call the “ART of Growing Tomatoes” because every soil type, season, and crop varies.
Next, know your tomatoes. Cherry and grape tomatoes are almost like weeds. They are easy to grow, and if you are a beginner, start here. Roma tomatoes are only a little more difficult to grow, and I love their dryer flesh especially in salads and sauces. BUT, the large sandwich or hamburger tomato is more difficult to grow. Heirlooms tomatoes are even more difficult to grow than hybrids. I recommend always planting some of a Tomato Spotted Wilt resistant hybrid like Amelia, Crista, Red Bounty, Bella Rosa, and etc. to make sure you have a least a few tomatoes then planting older hybrids or heirlooms to finish out your planting.
Finally, know how, when, and where to plant tomatoes. Large tomato plants can be planted deep or laid down in a trench, but always protect the stem at the ground level with a 4 X 6 inch piece of aluminum foil. Wrap the foil loosely around the stem without getting soil between the stem of plant and the foil and plant with 2 inches of the foil above the ground to protect against cutworms and 2 inches below the ground to protect against Southern Stem Blight. In our heat tomatoes need to be planted early (April) or in July for fall harvest. This is important so that fruit can be set on the plants before it gets real hot. Tomato flowers will not set and will fall off the plant if nighttime temperatures are above 76 degrees. This is one reason why full season (indeterminate) tomatoes like Better Boy or Whopper only bare fruit in early summer and again in fall skipping the hot summer. Tomatoes should NOT be planted in soil that is too wet, too dry, too shady, or where tomatoes have been planted in the last 3 years.
The Clemson University Cooperative Extension Service offers its programs to people of all ages, regardless of race, color, gender, religion, national origin, disability, political belief, sexual orientation, marital or family status and is an equal opportunity employer.
— Tony Melton, Florence County Extension Agent
For more news from South Carolina, click here.