Once your seeds have germinated and have started to grow, you need to think about the next step in the process which is transplanting. Transplanting is the process of moving a plant from one location to another. In this case we are moving the young seedling from its spot where it was sown in a flat or other container to its new container where it will be left to grow big enough to be moved outside into the garden.
It is time to transplant when you see the first set of “true leaves” starting to grow on the seedlings. The true leaves usually look quite a bit different from the first set of leaves (cotyledons).
As in sowing seeds, your transplant container and soil should both be clean. The soil you use can be coarser than the soil the seed was sown into. Moisten the soil mix before transplanting.
Using a spoon, knife or other tool gently lift the seedlings from the soil. If you end up with a bunch of seedlings stuck together, separate them by gingerly teasing the roots apart.
Always handle seedlings by their leaves and roots; avoid crushing the stem.
Make a hole into the soil of the container receiving the transplant and place the seedling into the new soil mix. Try to keep the roots from curving upward if you can. A slim stick or similar tool can be used to guide the roots into the soil.
Then very gently tuck the soil around the roots.
Water the seedlings using a watering can with a very fine stream or, if the seedlings are small, set the container into a pan of water and let the moisture wick up from the bottom. Let the excess water drain away.
At this stage most seedlings will not need to be covered with plastic. Place the newly transplanted seedlings back under the grow lights or in a sunny window. Keep an eye out for signs of low light; these include elongation of the stems and/or leaning toward the light source. Raise or lower your grow lights as needed to keep the plants within two to three inches of the fluorescent tubes.
Continued use of a small fan to direct air over the plants is still a good idea at this stage.
Maintain your water and fertilizer schedule as before.
When the transplants get big enough, they can be moved out into the garden. Before that happens however, they need to go through one more step. We’ll discuss that in the next post.