Winter Cover Crops

by Solstice Farm Owner/Operator Bradley Capron

Missed out on Planting your Fall Garden? Try a Winter Cover Crop and get a Head Start on Spring!

Winter cover crops are a great way to build soil, and are a common sight on organic farms, and increasingly so on conventional farms. Cover crops have several benefits depending on the varieties of plants, including:

Building Nitrogen
Adding Carbon/Organic Matter to Soil
Pulling Nutrients and Minerals from the Sub-soil
Penetrating and Breaking up Soil Compaction with Strong Root Systems
Suppressing Weed Populations and Germination

The winter climate of your location will greatly influence the type of plants that can be put in, but there are good choices for virtually all locations. When possible, combinations of plants give better results than monocrops.

The most common winter cover crop is clover. It germinates well even in cold fall conditions, or windows of favorability in the winter. It is great for building nitrogen that forms in association with bacteria on the roots. Don’t forget to buy inoculant for the seed! It pairs well with rye grass or fall planted oats that act as a nurse and shade crop, and produce additional biomass for soils low in organic material.

Mustard greens are becoming increasingly popular as winter cover crops. They do a great job of ‘fumigating’ the soil, so if there was heavy disease pressure due to excess rain in the summer and fall, a mustard cover crop can cleanse the soil between crops to reduce future incidence. It also produces a great winter forage crop if you have chickens or other farm animals.

Daikon radish is a great choice for heavily compacted soils, as the long tap roots reach deep, and then winter kill in cold climates (or can be closely mowed in warmer ones), leaving behind deep channels into the subsoil for moisture and nutrients to penetrate.

Vetch is another good choice. It is similar in function to clover, being a legume, and builds nitrogen and biomass accordingly. Highly recommended to plant with a grass to allow vetch to climb.

For market farmers, or areas with higher fertility that need a place holder cover crop that can also fix some nitrogen, I recommend field peas. They make great pea shoots, which are popular with restaurants and tasty on salads. Peas are not a great choice for poor and heavy soils as they have a weak root system. They thrive in areas that previously had a high demand crop like peppers or tomatoes.

All these cover crops can be mowed, cut, or weed whacked in early spring, then tilled in, or left on the surface and top dressed with compost for no-till systems. Cover crops are an economical and effective way to build soil nutrition and structure, and make a great pre-cursor to market crops or home gardens.