All About Cover Crops: Steps to Successfully Use Cover Crops on a Small Farm or Garden
Crimson Clover cover crop
Updated April 22, 2023 // Originally Written on July 13, 2016
Cover cropping doesn’t have to be hard, despite how difficult and confusing it might seem. Basically all we do is broadcast seeds in garden beds, let them grow until they are about to set seed, then mix their decayed foliage and roots into the soil as green manure.
Below, I go into detail about how that process works.
Frequently incorporated into organic and regenerative farming systems, cover cropping is absolutely a practice we can adopt in smaller farms and backyards. We can even cover crop raised beds that are just a few feet long! By selecting the proper cover crops for your space and timing the seeding right, a wealth of benefits await.
Related: How to Fix Soil After Using Miracle-Gro and Other Chemical Fertilizers
How Cover Crops Work and Why We Use Cover Crops on our Flower Farm
Cover crops break up hardpan soil with their incredibly strong root systems (alfalfa, mustard, daikon radish);
As cover crops decompose, foliage and root systems feed a diverse variety of microbes, especially important over winter;
The thick layer of cover crop residue leftover on the soil surface protects soil from erosion, moisture loss, overheating and heavy rains;
Cover crop roots leave behind a ton of rich humus, deep underground. Extra humus and organic matter means the soil has the ability to hold more moisture. Increasing soil moisture holding capacity is imperative in areas of drought;
Legume cover crops (clovers, field peas, cowpeas, hairy vetch) fix nitrogen from the air and deliver it to their roots in small nodules, replacing nitrogen that was used up during the growing season;
Cover crops suppress and choke out weeds, especially buckwheat in Summer and clovers/peas in Spring;
As they are incorporated back into the soil in the spring as Green Manure, decomposed cover crops add tons of organic matter to the top layers of soil, along with tons of food for Soil Food Web organisms;
All cover crops produce beautiful flowers that feed pollinators.
Tips for Successfully Cover Cropping a Small Farm or Backyard Garden
how to choose Cover Crop Varieties
My method for choosing cover crops is simple: Choose 3-4 different types of cover crops, mix them up together in a bucket, and sow them all together. Using a mix of cover crops, rather than one single variety, will address multiple issues, such as breaking up hardpan soil, improving soil tilth by adding lots of biomass/organic matter, adding nitrogen for the following crop, etc.
Timing cover crops for good germination
The trickiest part of choosing cover crop varieties is making sure you choose seeds that are appropriate for the time of year you want to use them. For instance, clover and peas germinate in cooler weather, so Spring and Fall are great times to use those. Buckwheat germinates and thrives in the hottest heat of the summer. Be sure to choose cover crops that will perform during the temperatures when you want to use them, otherwise you will waste a lot of cover crop seed when they don’t germinate because it was too hot/cold out!
A wonderful chart for timing and choosing cover crops can be viewed here.
Related: Winterizing the Flower Farm Using No-Till Soil Building Techniques
pro tip: seed cover crops right before it rains
Cover crop seeds, like all seeds, need adequate water to germinate. If you seed cover crops in the middle of a summer drought and have no way of watering the seeds in, you’ll have wasted all that seed (or you’ll have provided a very expensive, curated breakfast buffet for the birds). Always cover crop the day before a rain, if you can. There’s no sense in wasting water by irrigating cover crop seed, if you can avoid it!
Related: Demystifying Compost: All the Questions You Need Answered About Compost
our go-to cover crop seed mixes for zone 6b
April seeding (40-60 degrees, lots of rain, cool days and nights) - crimson clover, hairy vetch, mustard, daikon radish/purple top turnip, oats
Summer seeding (Hot!) - buckwheat, millet, amaranthus, sorghum
Fall seeding (September when its raining/cooling down) - winter rye, oats, hairy vetch, crimson clover
how to apply cover crop seeds in the field
To actually get the cover crop seed onto my field, I do it by hand with the broadcast technique. “Broadcasting” is a hand sowing technique where we simply take a handful of seeds and throw them/broadcast them over a large area while walking. It takes practice to perfect the flick of the wrist. It’s an effective way to get a lot of seed down without equipment, such as a walk-behind seeder or tractor with a seeder attachment. I happily hand-broadcast cover crops over 1/2 acre patches of the field at a time.
Pro Tip: Mix seeds of the same sizes in separate buckets. I recently cover cropped a section of my field with hairy vetch, oats, crimson clover and mustard. While the hairy vetch and oat seeds are much larger, the clover and mustard seeds are tiny in comparison. When all four of those types are mixed in the same bucket, the small seeds tend to fall to the bottom, which means the handfuls of seed I’m grabbing are not mixed properly. So I mix the larger seeds together in one bucket, the smaller seeds together in another bucket, and grab from each bucket while broadcasting. Perhaps I just need a pair of overalls with two really deep pockets… now there’s an idea.
Related: How to DIY a Seed Starting Setup
terminating cover crops
The absolute most important thing you must do before cover cropping is decide how you’re going to terminate the cover crop when it’s reached peak growth.
I cannot stress how important this is. If you let cover crops grow past their peak because you didn’t have a plan in place, the cover crops will drop seed and become a weed on their own.
Options for terminating cover crops are as follows:
Use a hedgetrimmer to cut down tall cover crops, then a mulching mower to kill the cover crop down as close to the soil as possible. Use a mulching mower in particular so all of the residue you’re mowing down stays on the garden bed. Then, cover with a silage tarp or landscape fabric for a few weeks to fully kill the roots and start to decompose the leftover cover crop residue. This is how we terminate tall cover crops such as buckwheat.
Check it out: My 80-volt electric hedgetrimmer and electric lawn mower that share the same battery.
Use a roller/crimper attachment on your riding lawnmower or tractor to break the cover crop stalks. You could also use a brand new, heavy roll of landscape fabric or something similar to crimp the crop down. Get creative! Then, cover with a silage tarp or landscape fabric to fully kill the crop.
Till the crop in. We grow in a no-till system and do not recommend the tilling method, but it is an option.
If the cover crop is short enough, you could forego using any of the above tools and simply cover it with a silage tarp or landscape fabric. This works well for clovers, turnips, radishes, and other crops with shorter tops.
There are 1,000 ways you could terminate cover crops. The most important point is to leave the residue and roots in place so all of that nutrition and organic matter can be incorporated back into the soil through soil microbial life.
how to plant after cover cropping
In our regenerative, no-till farming system, we terminate our cover crops using a combination of a hedge trimmer, mulching lawnmower and silage tarps. Once the cover crop has fully died underneath the tarp, we cover the bed(s) with a fresh layer of compost and plant right into the residue. If we have time, we will broadfork the bed, after adding compost, to work on breaking up our clay hard pan. We make sure to leave all cover crop roots and residue in place for the worms and soil microbes to break down and deliver nutrition to our future crops.
Related: Why is Tilling So Bad?
sourcing cover crop seeds
We buy huge 50-lb bags of cover crop seeds, and shipping can get expensive on those items. When possible, we source cover crops from our local feed store — many of these seeds are sold as bird feed, chicken feed, horse feed, etc. I’ve successfully found buckwheat, millet, winter rye and oats locally.
If I can’t source cover crop seeds locally, I prefer to buy them from Outside Pride. They have great quality, great selection with lots of different weights, reasonable prices and prompt shipping times.
Related: Our Favorite Resources for Vegetable Gardening: Books, Tools, Soil Amendments & Sourcing
silage tarps for cover cropping
Silage Tarping is a topic for a whole other blog post, but you can find smaller sized silage tarps here. Thickness should be 6 mil — anything less than that and it will rip to shreds.
Good luck cover cropping! The only way to learn is to try, so get out there and try!
peace, love, and food for soil microbes,
fran parrish
