If you hang around vegetable gardening circles long enough, you are bound to hear the phrase “green manure“. You may start thinking folks are talking about some weird green cow poo, but it is quite the contrary. Using green manures can greatly benefit your soil composition, which in turn will benefit your vegetable production.
What Is Green Manure
Green manure is simply plant vegetation that is grown in the garden, then cut down and dug in to feed the soil. Crop rotation is a very common practice in farming. One year a field would contain a particular crop, then the field was left bare (or fallow) the following year. This was done to give the soil a chance to replenish nutrients. It was found in studies that the fallow field actually lost more nutrients due to water runoff from rains, snow, the sun, and winds that would blow topsoil away.
This is when the idea of implementing cover crops began. Growing cover crops helped to eliminate the erosion issues. The cover crops were then chopped down and dug in to the soil. Doing this benefited the soil by adding organic matter, and supplementing key soil nutrients.
What Are The Best Plants To Use for Green Maure?
Just about any vegetation can be used as green manure, but there are some plants that add special elements to the soil. Here are just a few:
- Crimson Clover
- Bitter Lupin
- Alsike Clover
These plants should be planted in late summer or in the fall.
- Red Clover
- Winter Rye
How To Use Green Manure In The Home Garden
Most home vegetable gardeners do not have fields to work with. There is not enough space to warrant leaving the garden bare for one full year while green manure plants are being grown. I know I don’t have the patience to wait a whole year to get my garden started.
One practice that a vegetable gardener can do is to use the vegetable plants themselves as green manure once the growing season has ended. Instead of pulling your vegetable plants up and discarding them, chop them down and let them lay in the garden for a couple weeks. Once they have begun to rot, chop or dig them into the soil with a digging fork. You can also scatter hay, grass clippings, or leaves across the garden space for added organic matter.
You can plant vetch and clover in between vegetable plants (and rows) when planting the garden to act as a living mulch. Once the growing season has ceased, they can be used as a green manure when you chop it into the soil. You will get two uses from the same plants – a cover crop during the season, and green manure after the season!
You can also use green manures just before planting your vegetable garden. Scatter a thin layer of hay across the garden space and let it sit for a couple weeks. Once it has started to rot, chop it in the soil and then plant your vegetables. You can also use alfalfa hay (like the kind used as rabbit feed) in the same manner for an added nitrogen boost for the soil right before planting. Using green manures is a great substitute for compost, if compost is not available or in low supply.
Do you use green manures in your garden?