Farmers see a variety of benefits when using cover crops in their fields and home gardeners can do the same.
“Having living tissue, living plants on the garden the whole year increases soil health, decreases erosion, captures nutrients so that they are being taken up by these plants that are there in the off season or in between plantings during the growing season, so that they're not leaching away or running off,” said Dan Fillius, a horticulture specialist at Iowa State University Extension.
Fall planting
Late August and early September is a great time to plant oats and peas.
“These are both crops that will winter kill, and now's a great chance to let them grow up as big as they can get, while also getting most of your growing season in there,” Fillius said. “So anywhere that is empty right now in the home garden. This could be in a raised bed. It could be in native soil right there at ground level.”
When the temperature reaches about 15 degrees they will stop growing and die.
“In the spring, when you go out to that space they'll be laying on the ground. They will rake off easily with a rake, and you'll be able to plant into there,” Fillius said.
If you still have plants that are producing, winter rye is a hardier cover crop that you can plant later in the fall.
“You may not see much of it over the winter, but in the spring it will take off,” Fillius said. And it's better to plant it late in the fall than it is in the spring generally, because when it does a lot of that prime growing in the spring the ground is too wet for you to really get in there and do much work.”
Spring planting
Cover crops can also be introduced during the growing season.
“Let's say you're planting, oh, three patches of green beans. You want a constant supply of green beans in your garden. You plant the first one in mid-May, at the same time in those other two patches you might consider planting buckwheat,” Fillius said.
About 10 days after it starts flowering you should terminate it to prevent it from setting new seed.
“But in those 10 days, it's going to provide amazing forage for bees and other pollinators out there,” Fillius said.
Management
The main challenge of using cover crops is that home gardeners don’t have a till or mower to manage the crops. But there are several at home management techniques.
Buckwheat is one of the cover crop varieties that must be terminated by gardeners themselves. This can be done by mowing it down to ground level with a string trimmer.
“The tops will lay down on the ground there. It'll provide some sort of cover. Or you could just take it and put it on a compost pile or use it as mulch elsewhere, but it is not going to come back after you string trim it off just above ground level.”
Other crops, like winter rye, can get six or seven feet tall. For these plants, Fillius recommends crimping with a T-post when the rye is just starting to flower, before it's actually pollinated.
“You take a rope connected to each end of the T post ... you can rock back and forth and crimp with just your body weight on that T post pushing down on the rye. [It] just lays it down and crimps the stock, which terminates it.”
Continue moving a couple inches forward and crimp progressively down the bed.
“It's intuitive, and it works way better than I thought it ever would. I have I planted pumpkins into there this year, and it just I don't have any weeds in that section.”
For more tips, consult Iowa State University Extension and Outreach’s materials on cover crops.
