Fall is the perfect time to start replenishing your soil after the intensive growing seasons of Spring and Summer.  Building soil health during the colder months is crucial for abundant harvests year-round.  The smaller selection of cold-tolerant crop varieties means smaller gardens, if any, in the Fall and Winter.  This means that the remaining space in your farm or garden may lie undisturbed until February or March.  There are many ways to build soil health but all of them boil down to one key element, increased amounts of organic matter in your soil.  This is commonly achieved through use of cover crops or mulch.  

This Fall at Pine Mountain Settlement School we are growing a small garden with cold-hardy varieties such as kale, broccoli, brussels sprouts, and a few others.  The remaining space in our high tunnels has been cover cropped, to build our soil health and get a head start on the success of our Spring and Summer plantings.  When selecting a cover crop for your garden or farm space it can be easy to get bogged down by the immense number of cover crop varieties available to you.  There are three basic families of cover crops and it is important to understand the benefits of each as well as the needs of your garden before making a decision.  

  • Grains – like annual grasses, rye, oats, and wheat  These crops have extensive root systems and break up soil compaction while also providing a lot of biomass.  Their leaves also improve water infiltration by slowing down the movement of water from rain or irrigation.
  • Legumes – like peas, soybeans, clover, and vetch  These are commonly known as nitrogen-fixers and each variety in this family offers slightly different benefits. 
  • Broadleaves – like buckwheat, mustard, and alyssum  These germinate quickly to shade out undesirables, like weeds, and smaller root systems make them easy to turn in for nutrient benefits.

Many seed companies sell cover crops as mixes with a combination of the families listed above to provide broader benefits.  Whether you choose a mix or a single variety your soil will appreciate the addition of nutrients and organic matter.  Another thing to be mindful of is different varieties need to be turned into your soil at different times.  Some cover crops should be incorporated into the soil before they flower and some after.  After the cover crop is turned into the soil it should be left for a week or two before you begin planting Spring and Summer crops.  

Mulch can be a great addition to Fall and Winter gardens as it contributes biomass over time without the competitive root systems of cover crops.  Mulch can also help protect your garden from the cold by insulating the soil, protecting plant roots and bulbs can protect them from the negative effects of temperature swings.  It also allows for worms and microbes to remain active during colder months, providing them with a warmer environment protects soil health.  Organic mulches like straw, shredded leaves, nut hulls, and wood chips are good options.  It is best to use  materials native to your area.