Submitted by Rick Thomason, UT/TSU-Johnson County Extension Director
The best way to get high quality, healthy, and true-to-variety vegetable transplants is to grow your own. If, however, you choose to buy transplants from a nursery or garden center, here are some suggestions for selecting and caring for transplants.
Choose transplants that have a dark green, healthy appearance. Generally, shorter, thicker transplants are much better than taller, skinny plants. Vegetable plants should not have flowers, as this will add to the stress of transplant shock. Carefully remove the plants from the container and examine the roots. Healthy plants will have white roots. If the plant roots are discolored or have a brownish appearance, this is a good indication that they are not healthy. Also, make sure that the plants are free of any insect infestations or obvious disease problems. If you don’t transplant your new seedlings immediately, be sure that the roots are kept moist, but be careful not to over water the plants.
When we are past the danger of frost, you can transplant the plants into your garden. In Johnson County, I estimate our spring frost date to be around May 15th. Of course every year is different, but during most years you are safe to move the transplants outside to your garden around mid-May. Just keep check on the extended weather forecast before transplanting.
At transplanting, be careful not to disturb the roots any more than necessary. The tiny root hairs are very fragile and are very important in supplying water and nutrients to the plant. The exception would be if you could only purchase transplants that are “root bound” with a thick bundle of roots winding around the root ball. In that case, carefully unbundle the root mass, without tearing the roots, if possible.
Most transplants can be planted to a depth equal to the depth of the roots in the container; however, tomato and pepper transplants will almost always perform better if planted deeper. These transplants can be planted up to their first true leaves. The stems will generate additional roots very quickly. Deeper planted tomatoes and peppers will soon surpass shallow planted transplants, and will develop better root systems and be much healthier all season long. This also helps to make them more drought resistant in the hot part of the summer.
Newly transplanted vegetable plants should be watered thoroughly for several days to help the roots develop more quickly and get established in the garden. A diluted starter fertilizer high in phosphorous can also help with root development. Be careful not to over feed the new transplants as tender seedlings can easily be “burnt” by over-fertilizing the plants. In addition, excessive fertilization early in the season will often cause more foliage development and may actually suppress flower and fruit development.If you have hungry wildlife in the area (rabbits, deer, groundhogs, etc.), you may want to shield your new transplants with small wire cages or fencing to deter their feeding activity.
At planting is a good time to identify your plants, especially if you’re growing several varieties and you want to compare results throughout the season. Use a waterproof marker to make plant labels or paint the plant name on a smooth rock that can be placed near the plant for identification. The small plant labels that usually come with transplants will soon be lost, so make big plant identification markers now if you want to know what’s what later in the season. By keeping good notes on the performance of your vegetable transplants this year, you will have some good information to help you have an even better garden next year.