New Tomato Seedling Transplants Not Growing

Q. I started seedlings in a greenhouse and transplanted them into my raised beds. but they are not growing at all. It's been 2 weeks, and a couple have died but the rest have not even continued growing.
A. Moving seedlings of hot weather plants like tomato, pepper and eggplant from a warm, still environment like a greenhouse into one with very different temperatures and wind like a garden can be quite a shock on young plants.

This kind of shock will lead to short term slowing of growth and changes in plant color as well. It can also lead to disease development if you are not careful.

Transplants like these tomatoes can develop problems when temperatures begin to cool. These tomatoes developed disease problems due to a combination of dirty growing conditions and hardening off for transport to the field.

In this case it is thought that Fusarium may be the problem by the symptoms displayed. Sanitation and weed control would have been an important step in preventing disease problems.

Plants respond to changes in the environment very differently from animals which have legs and can move to a more hospitable environment. We try to move these transplants progressively/gradually into these less hospitable environments.

This is called “hardening off” a plant. This can be opening the greenhouse so that the outside environment starts mixing with the hotter greenhouse environment, moving them into a garage first with the door open for light, moving them outside into a shaded and protected environment for a couple weeks before planting them, etc.

There is a transition period when the transplant will show no signs of growth while its root system begins to grow into its new environment. The larger the transplant, the greater the transplant shock or time needed for it to adjust to its new environment.

However, these problems can occur if planted incorrectly:

• Make sure you planted transplants the same depth in the garden they were growing in the pot. The only exception would be tomatoes which you can plant deeper than that and the stem below ground will root into the garden soil IF the garden soil is adequately amended. I just replanted a pepper plant for a friend who had planted it too deep. The pepper was just sitting there, the leaves were scorching, until I replanted it to the right depth. Then the new leaves showed no signs of scorch and the plant “took off”.
• Do not plant peat pots directly into the garden. These peat pots or other pots for transplants that are supposed to degrade in the garden soil often times can create problems and restrict water movement in the area of the pot. Remove as much of it as you can without damaging the roots of the plant.
• If you do have peat pots or coir pots and planted them with the transplant, tear off any part of the pot sticking above ground so the water in the pot does not “wick up” to the outside air and dry out the root zone.
• Make sure the soil drains adequately and give it lots of water. Give it some protection from direct winds by putting up a small windbreak for the garden.