Who knew? Carrots grow extensive networks of thin roots before they grow the tap roots of which Bugs Bunny is so fond.
When I decided to experiment with growing a small kitchen garden in ultra-cheap planters, I hoped to come up with a few space-saving ideas that would be easy on my budget. I had no idea I’d learn something cool about carrots along the way: carrots make a lot of roots!
On May 1, I described how I modified a two-liter soda bottle, filled it with soil, and planted eleven carrot seeds in it. Seven weeks later, the carrot plants are growing well; their tops are beautifully lacy-green. You can read about it here: Small Kitchen Garden Carrots in Containers.
What’s Going Down?
In my fortyish years of growing carrots in a garden, to me these plants have always been green fluffy greens that grow atop orange shoulders just showing above the soil. At harvest, I’ve found smooth orange tap roots of various lengths, tapers, and diameters. One season, I left carrots in the ground well into winter. Along the way, flowers emerged much like those of Queen Anne’s Lace (carrots and Queen Anne’s Lace are closely related), and the plants put up a second wave of foliage. When I excavated these very mature carrots, I found many small roots growing from the plants’ tap roots. These mature carrots looked hairy, and somehow much less appetizing than younger, smooth-skinned carrots.
But you know what’s cool? Before a tap root forms, a carrot plant puts out a huge network of tiny roots. Who knew? You can see these roots through the clear side of the soda bottle planter in which my carrots are growing. The roots have been visible for about four weeks, and orange carrot shoulders have yet to appear at the bases of the foliage.
This upside down tomato plant supports the observation that roots want to grow down. When I planted the seedling, its root ball topped out about two-thirds of the way up inside the planter. A week later, though many roots are visible through the plastic, none appear above the root ball.
Of course, it makes perfect sense that the plant would need roots to get established before it built up its winter food supply in a tap root. Still, I’d never thought of this, so creating my silly soda bottle planter led to the pleasant surprise.
About Upside Down Tomatoes
When I wrote about growing tomatoes in upside down planters I predicted that roots would immediately start growing down from the root ball of the newly-planted seedling. Eventually, I guessed, an upside down tomato plant would become pot-bound even if there were many inches of soil available above the root ball in the container.
I don’t know whether I’m right about this, but I can report that all the root growth in the first week has been downward. How do I know? I followed instructions at http://ohcripes.com (once you’re on the site, look in the left margin for the link to IPlanter Modified) for creating an upside down planter in a three-liter soda bottle. I set a tomato seedling in my planter and hung it up last week. Already, new roots have grown from the root ball out to the sides of the planter, and then down along the sides. No visible roots have grown upward. This may change as the plant becomes pot-bound, but I don’t expect it to.