"I'm confused about rye and buckwheat. I have used them before and tilled them in, but, with the no-till method, how does just cutting them down allow you to plant something else in their place? Would the cut areas not resemble cut grass (for the rye) with the root mass still present? How do you plant in this?"

--- Heather W.

Even though I've written an entire ebook on the subject, I still get this question quite a bit, so I thought I'd answer it in a post.  The trick with mow-killing cover crops is to understand the plants' life cycle.  Lawn grasses are perennials, but the cover crops I'm writing about are all annuals, meaning that they sprout, grow for a while, then bloom and push all their energy into a seed.  After blooming, annuals naturally die and leave the ground bare for whoever comes next.

While you can wait for these annual cover crops to go to seed and perish on their own, you'll then end up with a weed problem in your garden.  Instead, I recommend mow-killing when cover crops have just reached full bloom, at which point the plants are totally committed to the reproductive process.  Plants that mow-kill easily will die if cut at full bloom, rather than regrowing like a lawn grass would.  You'll still have a lot of root stubble, which I recommend topdressing with a healthy dose of compost and letting sit for a few weeks (for rye) so that microorganisms will turn the roots into humus.  After that, the ground will be bare and ready to plant into.  (Buckwheat is so succulent that you can plant into the stubble nearly immediately.)

Not all annuals mow-kill readily, of course, and if you don't pay attention to their life cycle, your mow-kill attempt will also fail.  For example, many of the annual grains will respond like lawn grasses if you mow them when they're young and in a vegetative growth stage.  And, of course, you shouldn't expect mow-killing to work on perennial cover crops.  I haven't tried all these myself, but Managing Cover Crops Profitably reports you'll have good results mow-killing the following cover crops: annual ryegrass, barley, rye, buckwheat, oilseed radishes, cowpeas (although my experience differed), field peas, hairy vetch, and woollypod vetch.  Finally, if you plan to mow-kill and it fails, there's always kill mulches.

For more information on integrating cover crops into a no-till garden, check out Homegrown Humus, only 99 cents on Amazon.