What is a Cover Crop?
Cover crops are crops planted to improve soil quality, fertility, water holding capability, weed control, pest control, and improve biodiversity. Typically cover crops are planted in a field or garden at a time of year when the land is fallow. This helps to limit any nutrient loss by having bare soil over the winter. Cover crops can be annual to limit competition with spring planted crops, but they can also be perennial, with many farmers tilling in the cover crop.
Common Cover Crops
Most cover crops fall into one of three categories: perennials, annuals for warm weather, and annuals for cool weather. They can also be broken down further into grasses, legumes, and non-leguminous broadleaf plants.
There are tons of varieties to choose from, but below is a list of those that I like and am familiar with.
Perennial Cover Crops
- Dutch white clover: This legume is a nitrogen fixer, pollinator attractor, and chicken forage species. It is also a good living mulch because it only grows 6-8 inches tall. For those of you who don’t like mowing the lawn, this would also make a nice low maintenance lawn. I have been planting this clover as a living mulch in my fruit tree guilds. It will also serve as my pathways in my garden.
Dutch White Clover
- Alfalfa: Another legume, so we of course get the nitrogen fixation, but it also makes good livestock feed. The roots dig very deep and pull much needed nutrients to the soil. This legume gets to be 2-3 feet tall, so it is too competitive to be a living mulch. I will be using this cover crop as part of my chicken forage areas.
Warm Season Annual Cover Crops
- Cowpeas: This nitrogen fixer is also a good insect attractor.
- Soybeans: This legume is of course a nitrogen fixer, and insect attractor.
Cool Season Annual Cover Crops
- Sweet Clover: Like all clovers, this clover is a good nitrogen fixer and insect attractor. They do grow tall though, in the 3-6 foot range.
- Oil Seed Radish: Most people don’t think of radish as a cover crop, but the make great dynamic accumulators. I wouldn’t plant radish alone, but they make a nice companion to clover and ryegrass.
- Annual Ryegrass: I like to use annual rye in situations where I just need a cover for the winter, and it is too late in the fall to put in clover or alfalfa. I am planning a big swale project for early November, so I will use annual rye to hold down my berms and protect the soil.
- Vetch: This plant is a legume, so you get the nitrogen fixation, and the insect attraction. The really nice thing about vetch is that it is hardy to 0 degrees.