Planting a cover crop after harvesting your vegetable garden is a great way to replenish soil nutrients (especially nitrogen), loosen the soil, rebuild soil structure, reduce weeds, and control erosion over the winter months. They also add some often much needed organic matter to the soil.
Wow! What a lot of benefits!
The practice of planting a cover crop to revitalize your vegetable garden soil is one way to make your garden more sustainable.
Winter cover crops, often referred to as “green manure”, are generally sown in the fall, allowed to grow all winter, and then are cut (if necessary) and tilled into the soil in the spring before the planting season. The nutrients that have been assimilated into the roots and foliage are then returned to the soil to be used by your vegetable plants during the growing season. Good stuff, right?
There are a variety of different types of seed that can be used for cover crops, but probably the most common are some of the rye grasses, clovers, alfalfa, oats, buckwheat, and various brassicas.
This fall Mark has decided to “reap” some additional benefits from his cover crops – at least the ones he planted in his vegetable garden. Instead of planting some of the more traditional cover crops, he decided to try some edible crops (edible to humans, that is) like winter lettuce, spinach, beets, daikon radish, kohlrabi, rutabaga, and turnips as a fall cover crop.
Back in early September, Mark planted a mixture of these seeds in the vegetable garden and they have been growing beautifully over the last month. The area has filled in well and formed a dense cover of deliciousness!
The lettuce is especially nice right now and, since the vegetable garden is here at the farm, we’ve all been harvesting some nice handfuls to take home. Before he let us loose in the bed, however, Mark was very careful to instruct us on the “proper” way to harvest these greens to maximize their effectiveness as a cover crop. According to Mark, one of the tricks to harvesting the lettuce when it is grown in a wide bed as a cover crop is to gather a handful and cut the leaves above the growing point with a sharp knife or scissors leaving the roots and crown in place.
This accomplishes two things. First, when the roots are left, they hold the soil in place so it is less likely to splash up and get the nearby lettuce leaves dirty – which means less time spent washing the lettuce in the kitchen. Second, since the lettuce crown is also left behind, it will soon develop new leaves and not only will you be able to harvest from the plant again but it sustains the “cover” in the cover crop. Seems ideal!
In a month or so we should be able to harvest some of the other crops like the beets, turnips, and kohlrabi. We’re already harvesting a few daikon radishes and they are delicious. I’m curious about the kohlrabi as I’ve never eaten it before. Mark insists that it is delicious and sweet when it matures in the cooler weather of spring or fall so I’ll have to give it a try. I guess we’ll have to minimize the harvest of the root crops to some extent though in order to maintain the benefits of these deep rooted vegetables as cover crops.
I am really interested to see how hardy the winter lettuce is and whether it will be able to survive some of the hard freezes we are sure to have in the not too distant future. I’m a little skeptical about that but time will tell. I’ll be sure to report back! It does seem like the ideal type of cover crop especially for a vegetable garden.
In the meantime, at least by Thanksgiving, I’m definitely going to harvest some of those rutabagas. When I was little, I hated them but my grandfather always told me that if I didn’t eat my rutabagas, I would get scurvy for sure! It scared me so much that I always (mostly) sucked it up and cleaned my plate. Ha! Now I like them! Maybe he was right, I haven’t gotten scurvy yet!
Until next time – Happy Gardening!