The "How To" Transplant Seedlings
Now that you’ve successfully grown some seedlings, there are a few things to take note of in the process of transplanting them into the garden. Like everything in gardening, there are always certain ways to do things. Knowing how to go about it will give your seedlings a great start!

Timing
The key to transplanting seedlings is timing. Seedlings need to be transplanted when they are big enough but not too big where their roots have become root bound.
ROOT BOUND: The roots of the plant have filled the container that they are in, and they have little to no room to grow further.

Signs of a Root Bound Plant
1. Stunted Growth
The plant can’t seem to get beyond tiny in size.
2. Slow or Stopped Growing
No matter how much you water or fertilize, there seems to be no progress in
growth.
3. Crowded Roots
Crowded roots means that you see a tangled mass of roots!
4. Wilting or Drooping Leaves
You've watered and the plant is STILL wilting or drooping! No change in its posture!