The Walden Effect: Farming, simple living, permaculture, and invention.

Killing cover crops in a no-till garden

Resprouted oatsAfter deciding between growing nitrogen and growing organic matter, the other main factor to consider when choosing cover crops for a no-till garden is—how will you ensure your cover crop doesn't keep growing as a weed and outcompete your vegetables?  While you can dig up cover crops or till them in if you're desperate, it's better to choose crops that are easy to kill without disturbing the ground.

In the summer, mowing is the best way to kill cover crops in a no-till garden.  Only a few cover crops are easily mow-killed, and even with those that mow-kill well, you'll want to plan your garden season so you can allow the crops to reach full bloom (but not set seed) before cutting them down.  Depending on the size of your garden, you may use a lawnmower or a scythe to do the mowing, or might simply yank up handfuls then lay the roots on top of the leaves on a sunny day.  The latter method is actually my favorite with buckwheat in the summer garden since I can often pull up a bed of buckwheat by hand in the same amount of time it would take to put the blade on my scythe or to get the gas mower started.

My other favorite method of killing cover crops in a no-till garden is to let winter do the work for me.  Here's where those of you gardening much further north or south than my zone-6 garden will have to do some experimenting (although Managing Cover Crops Profitably does provide zone-related tips on where certain crops will winter-kill).  When I Laying down a kill mulchplant oilseed radishes and oats in the fall, cold weather naturally wipes out nearly all the plants during the winter, producing a mulch that rots into the soil by early spring (for oilseed radishes) or by early summer (for oats).  Homegrown Humus provides planting dates for those of you who want to experiment with winter-killing.

Although mow-killing and winter-killing are my favorite ways to kill cover crops, it's worth having a couple of other techniques up your sleeve in case your experiments don't go as planned.  A kill mulch is an easy way to kill just about any plants as long as you have a month or two to wait before planting the next crop.  Simply mow your cover crops as close to the ground as you can, lay down corrugated cardboard (being sure to overlap the edges by at least four inches so plants can't sneak up between layers), then top it all off with straw (or another vegetable-garden-appropriate mulch).  Lack of sunlight will kill all but the most ornery plants in short order, at which point you can either cut holes in the cardboard to plant directly into the soil, or can move the cardboard to kill mulch a new garden area.

Weeding up cover cropsIf you don't have time to kill mulch and you really need to get rid of those cover crops, you'll be forced to pull them up by the roots.  I actually use this method often with buckwheat, which is very simple to tear out of the soil, but weeding out most other cover crops will be a lesson in patience.  Good planning ensures you won't need to pull up cover crops by hand very often.

Learn more about cover crops that are easy to kill in a no-till garden in my 99 cent ebook!

This post is part of our Homegrown Humus lunchtime series.  Read all of the entries:

Anna Hess's books
Want more in-depth information? Browse through our books.

Or explore more posts by date or by subject.

About us: Anna Hess and Mark Hamilton spent over a decade living self-sufficiently in the mountains of Virginia before moving north to start over from scratch in the foothills of Ohio. They've experimented with permaculture, no-till gardening, trailersteading, home-based microbusinesses and much more, writing about their adventures in both blogs and books.

Want to be notified when new comments are posted on this page? Click on the RSS button after you add a comment to subscribe to the comment feed, or simply check the box beside "email replies to me" while writing your comment.

Hi Anna--great posts about cover crops. I've been wondering for awhile what the exact purpose is for the vegetation/straw mulch atop the cardboard. Is it just to hold down the cardboard or does it go beyond that? Thx!
Comment by jen g Thu Jan 24 19:58:54 2013
Jen --- The straw holds down the cardboard if you have wind, but mostly it's handy because it keeps the cardboard damp. If the cardboard dries up, it doesn't rot quickly, and can actually keep rain from soaking in. Cardboard covered by straw keeps fungi happy and promotes fast rotting.
Comment by anna Thu Jan 24 20:08:03 2013

profile counter myspace

Powered by Branchable Wiki Hosting.

Required disclosures:

As an Amazon Associate, I earn a few pennies every time you buy something using one of my affiliate links. Don't worry, though --- I only recommend products I thoroughly stand behind!

Also, this site has Google ads on it. Third party vendors, including Google, use cookies to serve ads based on a user's prior visits to a website. Google's use of advertising cookies enables it and its partners to serve ads to users based on their visit to various sites. You can opt out of personalized advertising by visiting this site.