It's late September in Maryland. The squash and okra are done and gone. Tomatoes and peppers following quickly. The only strong production really going on is sweet potatoes, and soon they'll be gone too. It's time to plant cover crops for the winter. Sure, we'll do some greens and beets and onions and garlic. But I want to keep my soil nice and safe for next spring.
If you're reading this, you probably already know all about cover crops and how they are the cheapest and easiest way to protect your soil and stop your soil nutrients (and your soil) from running out on you over the winter months. If not, just take a cruise through my cover crop and no-till blog tags. There are tons of reasons why people plant winter cover, including those listed above. But getting your urban or suburban garden to actually meet those objectives is a lot more complicated than just throwing down some deep-rooting hardy seed. Here are the basic steps.
1. Know what cover crop species you're planting well in advance of the planting date.
Do your homework - your state extension service is a great resource for choosing species and for planning for planting dates. Here's an example from Indiana:
|Dubois County Soil & Water Conservation District's Cover Crop Web Tool|
For existing gardens, just clear out dead summer crops, kill any and all pervasive weeds, and rough up the surface to the planting depth (usually less than 2 inches), either in rows or across the entire bed. If you have a seed drill, that's even better, but a seed drill doesn't punch through rocks, bricks, or mulch in your garden, so make sure to remove all debris. The key here: make room for your new seeds.
|The bed on the left has been (largely) prepared for winter cover crop seeding. |
The bed on the right contains late-growing sweet potatoes.
|Oats and peas for winter 2011-2012|
4. Plant based on real information, either from the seed dealer or from your local extension agent. For example, based on your garden's soil, do you need to buy legume innoculant? Sometimes, blog information can be helpful, too. Example: my cover crop test from last winter. It's not scientifically validated, but a decent guess at what you're getting yourself into.
5. Don't be afraid to experiment. Try different planting methods. Different species. See what happens. One tip: unless you love spraying herbicide on your garden, don't use cover crops that will not succumb to spring mowing, especially if you are interested in no-till, as I am. If you search the internet for "harvest green manure" followed by the species you planted, you'll see how to deal with the greens next spring.
6. Give your soil every possible advantage. That's what this is about, right?
a. If you plant winter cover in rows (as I did), backfill the rows with compost instead of garden soil.
b. Mulch the garden very lightly once the cover crop is 6-8" tall.
c. After you've planted it (ideally, before), read up on your cover crop species - how deep does it root? How effective in removing soluble nutrients? Protect from rain and snow runoff?
7. Don't be despondent if the cover crop looks weak in the spring. While a poor cover crop may not accomplish all of your goals, if it "sort of lived" through the winter, your soil is better off than it would have been without the cover crops. Every pound of soil you keep in your garden is a pound that doesn't end up in your local creek - and a pound of topsoil you don't have to buy at your local garden center.
|My various covers from Spring, 2011. Look at those peas!!!|