Green manure is another name for cover crops and most organic farmers grow green manure for the following reasons.
- Organic pest control
- Organic weed control
- Erosion prevention
- Disease prevention
- Adding nutrients to the soil.
So for this article, imagine that you live in dry climate and want to enrich your soil. Since you are organic farmer you decide to solve the problem with green manure. Next you decide on Alfalfa as it has very deep roots. These deep roots bring up nutrients from deep down in the earth to enrich your top soil.

Here is a picture of a Healthy Alfalfa field after growing a green manure crop last fall. The cows give their three tails out of three tails swishing approval.
So here is the process on how to grow green manure.
First, you have to plant the seeds or transplant seedlings to grow into green manure. Sowing (a fancy word for seeding) your seeds is pretty simple. Have you ever reseeded any spots in your lawn? It is a simple process.
- Gently work up the soil with a rake for small areas. For larger areas, we would use a piece of equipment like a spring tooth harrow (an older tool and is used to loosen soil prior to planting). There is also a disc harrow, that is a bit better, but we always used a spring tooth harrow.
- Now it is time to throw or “cast” your seed. Then you cover up your seeds to prevent the birds from eating it all!
- You want to plant your green manure crops in plenty of time to allow them to be healthy prior to frost, generally about 4 weeks before a “killing frost”.
- If you have row crops, you can start your cover crop before harvest time up to 4 weeks before harvest, by planting in between rows.
- Now it is time to take care of your green manure crop
- Mow your alfalfa cover crops to keep them manageable. You want them to stay growing and flexible, and it also helps increase the growth of the roots
- Some clover plants grown in garden pathways need to be mowed on a regular basis otherwise they will compete with vegetables and other flowers
- Be sure to water cover crops during times of drought.
Now the final step in how to grow green manure, kill them.
I know that it sounds harsh, but here is what and why you do that:
- Keep them from setting or (going to) seed
- That prevents the top growth from going crazy and becoming “woody”
- Cut them down to the base of the plant
- The woody plants do not compost as fast, and are more difficult to cut up with your tiller or by digging them up by hand.
- After a couple of days, when the leaves and plants are brown and dry, dig them in or till them into the ground.
- Keep them cut low by mowing over the winter. Do not let your cover crop “manure” get too big. It is just more work for you.
It will not take too long for the crops to decompose when you follow this plan of action.
It is best to wait 2 to 3 weeks before planting your vegetables after burying a green manure crop that consisted of grass plants. Some cover crops will hinder germination of your regular crops if planted too soon.
This is a basic guideline for you in how to grow green manure. Growing vegetables organically is a great way to save money and energy.
You can learn more by signing up here for our newsletter, and get a gift to help you increase profits from your home and garden.
Turning Your Dreams into the Life of Your Dreams
Founder hisfarm.org and Ambassador of Natural News and Sustainable Living on How to Live on Purpose.com