How To Use Cover Crops in the Home Garden

We often hear of cover crops used on large scale farms but what about the home garden? I’m here to tell you, you can do this as a home gardener and it will improve your garden soil and as a result your yields. I personally have used several cover crops in my home garden and they are worth the effort and not hard to do.

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What are cover crops and why would you want to use them?

Cover crops are grown with the purpose of improving the soil rather than for crop yield and harvest.

Cover crops have many benefits like:

  • improving soil fertility

  • preventing soil erosion

  • breaking pest and disease cycles in the soil

  • adding organic matter

  • increasing the biological life in the soil

  • suppressing weeds

What do all those benefits equal in the end? Healthy soil and consequently INCREASED YIELDS. All gardeners want that right?!

How do you grow cover crops?

Sow cover crop seed into loose and weed free soil. Seed planting depth depends on which specific cover crop you are sowing. But for the most part, cover crops can be broadcast and raked into the soil. It’s very easy!

After planting, keep the soil moist until the seeds germinate. Continue to water as needed until they flower. Once those flowers come out you need to kill the cover crop within 7 days. If you leave them longer they may go to seed and become a weed in your garden bed.

The best practice is to leave the roots, leaves, and stems with the soil after terminating the cover crop to break down. It allows you to get the full benefit of the nutrients from the cover crop.

To kill them at flowering there are several options: you can mow them down, weed whack them, pull the roots and till them back into the soil, or cut them. Remember to leave any plant matter you chopped or pulled with the soil to die.

After a few weeks the cover crop will be dry. At this point you can till it into the soil or if using no till, just leave it on top of the soil as a mulch.

What are the best cover crops for home gardeners?

In my opinion the best cover crops for home gardeners are easily killed and worked into the soil.

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Hairy Vetch is my favorite cold season cover crop. I can sow it in fall and it will grow slowly all winter. In spring it flushes out a bunch of growth and is usually ready to kill before I set in my summer crops. Hairy vetch fixes nitrogen in the soil.

It is great for northern climates as well. Just remember that it needs time to germinate and get going a bit before your first fall frost. I would make sure you get it planted at least 4 weeks before your average last frost in your area.

Peas and oats at flowering

Peas and oats at flowering

Peas and oats Right after pulling the crop to terminate it.

Peas and oats Right after pulling the crop to terminate it.

Field peas and oats are great for spring. They are very easy to grow. They are a good combination because the oats will support the peas. Field peas and oats add nitrogen to the soil and of course organic matter.

For warm weather the best cover crop is buckwheat. It quick to grow (35 days) and adds phosphorus and organic matter to your soil.

Hairy vetch, field peas and oats, and buckwheat are all cover crops I have grown before and personally recommend because I know they work and they are easy to use.

Other cover crops that may be worth growing in the home garden:

Crimson clover, white dutch clover, and Australian winter peas

One caveat, I’ve never actually planted white dutch clover because it is naturally occurring (aka a weed) where I live. And to be honest, it can be kind of pesky and hard to get rid of in my opinion. But I’ve heard good things about it as a cover crop which is why I feel it worth mentioning.

So what about other legumes like beans and peas? Can you plant beans and peas to enrich the soil and get a harvest too?

The answer to that second question is no (for the most part) and let me explain why. Beans and peas do add nitrogen to the soil. However, if you grow a cover crop past the flowering stage to where it is setting seed the nitrogen moves from the roots, leaves, and stems, up into the seeds. Roughly 80% of the nitrogen is stored in the seeds and when you are harvesting those seeds to eat (as in beans or peas) there is very little nitrogen left in the roots, leaves, and stems of that plant enrich the soil.

Purple Beans

Purple Beans

If you were to grow them for the purpose of a cover crop and cut them back at flowering, then they would add more nitrogen to the soil, and thus be much more beneficial.

Do you need to rotate cover crops in the garden like you would crops grown for food?

Rotation of cover crops is usually not an issue in the home garden. The only cover crops that may worth rotating are a cover crop of peas and cover crop of the brassica family. Using brassicas as a cover crops every year may make it more likely for club root to happen. Using peas every year as a cover crop has shown to have some detrimental effects on the soil. If you were to use the peas other year, that would be ok!

I never think about rotating cover crops much because I'm usually not cover cropping my whole garden every year. Because I have food crops in my garden through winter and my garden is also under very heavy production (I'm trying to maximize a small space), I put in cover crops where I can. My aim is to get every garden bed cover cropped once every 2 years. In the case of cover cropping every other year, you should have no need to rotate cover crops.

One other thing of note, if you do plan on cover cropping with peas and then are planting peas as a food crop in the same spot again that year, I would shy away from that. The same is true with the brassicas.

Conclusion:

  • Cover crops increase soil health and result in increased crop yields.

  • Home gardeners can grow cover crops easily!

  • My favorite cover crops for a home garden are hairy vetch, field peas and oats, and buckwheat.

  • To get maximum benefit from your cover crop, kill the plant at flowering and leave all the plant matter in the soil.

Further Reading:

https://www.sare.org/Learning-Center/Topic-Rooms/Cover-Crops

https://aces.nmsu.edu/pubs/_a/A129/

https://www.gardenmyths.com/legumes-add-nitrogen-soil

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