Time to move your seedlings to larger quarters. But how? Photo: greenbeanconnection.wordpress.com
If you have young seedlings that are packed too tightly in their original pot and want to transplant them into more spacious containers, here’s how to do it.
First, understand that seedlings can be transplanted into individual containers, such as pots or cell packs, or into larger shared containers, such as seed trays. Many gardeners, though, take advantage of this step to transplant their seedlings into cell packs, plastic reusable inserts composed of multiple individual growing compartments (6, 9, 12, etc.). The advantage of these cells is that the seedlings will be later easier to remove with their root ball fully intact when the time comes to transplant them into the ground or an outdoor container.
Step by Step
1. First prepare the planting container(s). Wash them (if recycled) and fill them with pre-moistened potting soil up to about half an inch (1.5 cm) from the top.
2. With a pencil or spoon, form a hole in the center to receive the seedling’s root ball.
3. Take the seedling between thumb and forefinger by a leaf (or cotyledon), never by the stem. (If you accidentally tear or crush a leaf, the seedling can grow a new one; if you damage the seedling’s only stem, it will die). With the other hand, slip a pencil or spoon into the soil under the seedling and, using the tool like a lever, push up while gently pulling on the leaf. The seedling will come out intact with a root ball covered in potting soil.
4. Gently set the root ball into the hole you prepared, at the same level as before. (You can bury more deeply, up to the level of the first leaves, those seedlings that have the capacity to form roots on their stem, such as tomatoes, peppers and cucumbers, plus cabbages and their relatives: broccoli, cauliflower, kale, etc.)
5. Fill the planting hole with potting mix and tamp down slightly.
6. Water very gently from above to complete the transplantation.
7. Place the seedling in a somewhat shaded spot for 24 to 48 hours before putting it back into full sun so it has time to acclimatize to the change. If you grow under a plant light, though: no acclimation period is necessary: you can put it back immediately under the light, less intense than the sun.
Extra Dense Seedlings?
Sometimes there are not just a few seedlings to divide, but a mass of them growing so densely together that separating them individually by the method above just won’t be feasible. If so, dig up the whole clump with a spoon and place it in a basin of tepid water as deep as the root ball is high.
The potting mix will start to fall away on its own, but you can also help by swishing the water back and forth a bit. Soon, the soil will almost entirely drop off and previously tangled roots will unravel as if by magic. You can then lift each seedling out of the water, again holding it by a leaf and supporting its roots with a pencil or spoon, then continue transplanting it as indicated above.
Illustrations by Claire Tourigny from the book Les semis du jardinier paresseux.