Extension Agent, Agriculture
NC Cooperative Extension
Granville County Center
January 2, 2014
Consider Growing Your Vegetable Transplants This Year
Growing your own transplants is a challenge, and it’s fun. Besides, you can realize a number of benefits by growing your own vegetable transplants. The major advantage is having plants of the varieties you want. You can grow just the number you need of each, and produce them as you want them. The hazard of importing pest problems is also reduced, and because you control the germination conditions, you get the maximum number of plants from costly seed. Vegetable plants can be grown under lights indoors, in cold frames, hotbeds, or plastic greenhouses.
Any shallow containers with drain holes can be used for growing transplants. For germinating, the flat inserts with narrow depressions for starter mix are very convenient. They are available at most garden stores. The medium for germinating seed should be sterile and uniformly fine. It should be well aerated and well drained, yet have good water retention properties. The commercial artificial starter mixes, available from garden centers, hardware stores, or greenhouses are excellent. You may use the same medium for growing the small plants up to transplant size.
Cool Season Vegetables
Four to six week old transplants of broccoli, cabbage, and cauliflower survive well in the garden and are frost tolerant. These vegetables can be started from seed indoors in early to mid February. They can be transplanted into the garden early to mid-March. Optimum soil mix temperatures for germination indoors is 70 to 80 degrees F. Seedlings should emerge in 5-7 days. Growing temperatures should be 60 to 70 degrees F. during the day and 50 to 60 degrees F. at night.
Warm Season Vegetables
Tomato transplants 6 to 8 weeks old may be set out after the danger of frost is past, during early to mid-May. Seed germination should occur in about 6 days with 75 to 80 degrees F. soil temperatures. Tomato seeds should not be started indoors until mid-March.
Pepper and eggplant transplants should be 6 to 8 weeks of age to be transplanted into the garden in mid-May. Seed should be started indoors during early March, with seeds germinating in about 2 weeks.
As soon as developing seedlings have their first pair of true leaves (the leaves that emerge after the seed leaves emerge), they need to be transplanted into individual containers such as styrofoam cups. Handle them by the leaf, not by the stem, so that you don’t crush them. Give them enough room. Crowded plants become spindly and weak.
Since seedlings of vine crops (cantaloupes, cucumbers, watermelon, and squash) do not transplant well if stems and roots are injured, and they are warm season vegetables, easily injured by frost, sow seeds directly into the garden in mid-May.
Remember to use fluorescent lighting indoors if you don?t have a cold frame or a greenhouse to start your transplants and never keep the lights more than 3 inches above the plants at any time, or they will become tall and spindly.
On April 15, we still have a 50% chance of frost to occur in our area. Remember that the chance of frost occurrence does not decrease to 5% until early May. Putting out warm season vegetables in the garden before that time increases the risk of plant death due to freezing temperatures.