When I buy my tomato plants from the local retailer, the root systems entirely FILL the little plastic "pot". They're absolutely root bound!! When I attempt the same for myself, the roots are shallow, sparse, and feeble. What am I doing wrong?
Growing Tomatos [or Any Plant] From Seed
Certified GKH Gardening Expert
Tomato plants grown in the greenhouse are grown at the perfect temperature with the perfect amount of light and fed to produce plants that can be shipped.
A crowded pot of roots is not necessarily better or healthier.
Here are some articles with more information.