by Rachel McAlister, Gardening & Agriculture Intern

Following each growing season, the soil—the most important agricultural resource—gets “worn out,” depleting nitrogen (N) and micronutrients. Home gardeners have several options for handling this: add organic fertilizer, organic compost, mulch, or cover crops.  

Cover crops are a genre of plants that restore soil. In some cases, they may even provide an edible product, such as clover flowers. Here are a few of the general benefits cover crops provide:
  • Increase nitrogen
  • Nutrient replenishment
  • Increased beneficial soil microbes
  • Weed suppression
  • Loosen compacted soil
  • Erosion control

Not every cover crop has the same benefits or is right for all areas. In the south, keeping your cover crops alive throughout the winter is not difficult-- there are several cold hardy varieties to safe-guard against cold snaps: 
  • Hairy Vetch (Vicia villosa) - Hardy to -15° F
  • Winter Rye (Secale cereale) - Hardy to -30° F
  • Crimson Clover (Trifolium incarnatum) - Hardy to 10° F
  • Dutch White Clover (Trifolium repens) – Hardy to -20° F.
  • Oats (Avena sativa) – Hardy to 10 to 20° F

To plant cover crops, prepare the soil as you normally would, tilling and then sowing the seeds at the appropriate depth (check the specifications for each crop). Many of these crops do not need excessive fertilization throughout the winter, as they can thrive on poor soils (and that’s why you want them in the first place!)

After winter and early spring the crops should be cut down, preferably before flowering. Rather than removing the cover crop from your garden altogether, work it into your soil or leave it above ground as mulch (the hairy vetch variety is ideal for this). Most large farms use a tractor to “crimp” the crop down into the soil, but in a home garden, a shovel will do just as well. And voila! You have green manure, as it’s called, giving you all the benefits of compost as the cover crop decomposes directly in the bed restoring any nutrients it used for growth.

So, rather than leaving your beds entirely dormant this winter, try a cover crop, improve your soil, and start getting your garden ready for next year early.