How to Terminate a Cover Crop for Green Manure

Learn how to improve the quality of your soil during the winter season! This step-by-step guide teaches how to terminate a cover crop without herbicides in 3 easy steps.

Who hasn’t wanted a better garden without spending lots of time and money?

A cover crop is an extremely inexpensive and easy way to improve the capabilities of your garden while you take the winter off. However, many people are intimidated by cover crops because they must be terminated prior to the spring planting season. 

It may seem like too much work, but investing this time now will pay off with better growth in spring and summer. The benefit of a cover crop isn’t just in the growing—it’s also in terminating it and creating what some call “green manure.”

Some gardeners do choose to spray herbicide to terminate a cover crop, but I think that expensive method is more harmful than it is beneficial. Instead, I’ll show you how to terminate a cover crop without herbicides easily.

What is a cover crop?

Cover crops are plants you grow in your garden during your off-season. They aren’t grown to sell or eat or harvest like cash crops. They’re grown to protect and enrich the soil.

These plants improve the quality of your soil and prevent erosion from washing away your garden. Many introduce more of those good, healthy microbes that help our flowers and vegetables flourish later!

Planting cover crops makes it more difficult for weeds to take root and become bigger competition to your cash crop later. Doing this also helps preserve that moisture conservation you work so hard to achieve during your grow season!

When you terminate or kill your cover crops, you want to allow the plant to decompose right there in the soil. This increases the organic matter in your soil and leaves nutrients right where your plants will want them come spring/summer.

Examples of Cover Crops:

I recommend broadcasting some turnips, kale, buckwheat, rye, winter peas and clover seeds across the garden area.  If you have trouble finding these seeds, you can look in the sporting goods section of most stores and find a wide selection of deer plot mixes that contain a great mix of seeds that will work well as your cover crop.

How do I kill a cover crop without herbicides?

1. Get your trimmer or weed-eater out and cut the cover crop from the top, moving slowly to the bottom of the plants. 
   This will allow your trimmer to work as a flail cutter and reduce the cover crop to small pieces.  Smaller pieces will till much more easily and decompose more quickly. Mowing the cover crop with a lawn mower will further reduce the residue’s size and increase the decomposition rate.
2. Once you have completed weed-eating or mowing the cover crop, let the clipping dry for about two weeks.
3. Till or Reduced Tillage method. If you are going to till now is the time to till, if you are going to use the reduced tillage method you should mow or weed-eat the area again very close to the ground to help kill off any remaining cover.
4. Allow the plants to decompose about 2 weeks before planting. 
   Waiting allows for the nutrients to begin breaking down and moving out of the plant fiber and into the soil. Once you plant your seeds or transplants, they will be able to find and absorb those nutrients for healthy growth.

What materials will I need to terminate a cover crop from my garden?

You will need three tools before you start:

• Trimmer or Weedeater
• Lawn Mower
• Tiller

How do you know when to terminate your cover crop?

Basically, you will need to terminate the cover crop 2-4 weeks prior to planting.  If you are planting late spring plants, you want to try to get rid of it before the cover crop develops seeds.

You DEFINITELY want to terminate the crop before it dies off. If you wait until this happens, the nutritional value will be lost and the soil will be dryer harder to till.

Tips and Tricks for Terminating your Cover Crop for Green Manure:

• Be patient — Start at the top of the plants and move down the plant slowly.
• If a stem is too tuff for the trimmer or mower to cut, you will have to remove the plant from the garden. Alternatively, you could break out the hoe and cut the plant into several smaller pieces.  Long stems or vines can reduce the productivity of the tiller by wrapping around the tines and making the task so much more labor-intensive than necessary.  
• Terminate the crop before it dies off. Otherwise, the cover crop’s nutritional value will be lost, and the crop will not be as easy to cut and till.
• Don’t plant immediately after terminating. To get the benefit of the nutrients, you have to wait for the crop to decompose.

More Garden Projects:

• How to Trench Compost – This composting method is a great way to improve your soil without a ton of effort. This is the perfect project right after Halloween to make use of fall decoration.
• Straw Mulch: How and Why – With inexpensive straw, you can benefit your garden in a multitude of ways!
• How to Build a Soil Sifter – Running your soil or compost through this DIY sieve is an easy way to increase aeration and improve drainage in your garden.
• DIY Pallet Compost Bin – This cheap project helps you organize your composting materials so that you always have a good supply for your garden!
• Guide to Winter Sowing – When you want to get the plants started before your garden is ready, some winter sowing in old milk jugs is an easy way!