My father-in-law happened to call me about a tray of veggie plants that had all become rootbound and, therefore, he determined they were no longer worth planting. On the contrary!
A plant with a small root system will have less chance of success than a rootbound one if (and I do mean IF) you've taken care of your plants prior to planting them. If you water the plants and then loosen the roots before planting, then a plant being a little rootbound shouldn't be a problem.
Seems like every spring I end up with several "stray veggies" getting planted here and there after I plant most of my garden, because I always get my favorites in the best spots first (certain varieties of tomatoes hit the different markets at various times). Then a little later, I come back and fill in with the extras here and there. During the days (and sometimes weeks) that I let these extra tomato plants sit in their little pots, I end up with a few rootbound tomato plants.
Has this ever happened to you? You buy a beautiful veggie or herb plant with intention to plant that day, but then time gets away from you, and when you finally remove the plant from its container, you find the white roots all balled up on the bottom (hence the name rootbound)?
There are several ways to go about loosening the roots. You can take a sharp yard tool and carefully slice, top to bottom, four equal sections around the plant. The slices should cut in about 1/2 inch into the dirt. Another option is to gently massage the bottom of the plant with your hand to loosen the roots up a bit. Don't worry about messing up the plant or breaking some of the roots, because the greatest way to keep the plant from succeeding would be to leave the roots bound up in a knot.
So I will tell you as I tell my three girls, "I don't know" is a reasonable answer to any question because it opens a door to learn something new. That was my first answer to my father-in-law, but then I started researching. There are so many wonderful opportunities to learn how to remedy a plant before you pull and toss it in the compost (or worse, the trash). As for me...that's the fun part of gardening...I'm always learning something new!
By Renee Adam