(By Laura Keir, Communications Coordinator)

You’ve harvested the last of your summer veggies and are getting ready to put your garden tools away until spring. But before you kick up your feet for the fall and winter, consider planting some cover crops and you’ll reap many benefits.  

Cover crops are temporary crops used in farms and gardens to naturally boost the productivity of the soil. They provide many benefits- depending on the type of cover crop planted- such as adding nutrients and organic matter, suppressing weeds, preventing soil erosion, and providing habitat for beneficial insects. 

If you want cover crops to overwinter, seeds should be planted by September or early October so they have time to establish (ideally about four weeks) before the weather gets too cold. You can intersperse cover crops between late season crops if you’re still growing and harvesting. 

Choosing the Right Cover Crop

If you’ve never used cover crops before, try starting with an easy crop like crimson clover. If you’re more experienced or have more space, planting a greater diversity of cover crops will be even better for soil health. To add more nitrogen to your soil, select legumes like clover, garden or field peas, alfalfa, fava beans and vetch. Grains like oats, cereal rye, wheat, and barley grow fast and provide a thick layer to keep weeds away.

To attract beneficial insects to your land, consider broadleaf plants that supply nectar such as vetch, buckwheat, and sweet, red and crimson clover. You can allow these to start flowering to provide bees with a food source when other flowers are scarce. But if you don’t want them around during your summer planting, be sure to cut them down before the seed heads start dispersing seeds. Or designate a space in your garden to permanently provide flowering cover crops.

Planting and Maintaining

Since your garden or fields have been busy producing all summer, it’s good to add some nutrients to the soil before planting to ensure the cover crops will thrive. Use compost or another type of organic fertilizer, and then follow the sowing instructions for the seeds you’ve selected. You may want to sow even more seeds than recommended, to ensure a dense canopy of cover crops.

Water your cover crop as needed until the rainy season sets in. For the rest of winter, you can sit back and relax as your cover crops grow!

Finishing the Cover Crop

In the spring once the ground has started to dry, it’s time to finish your cover crops. You’ll want to do this at least three or four weeks before you start planting in the spring, to allow time for the cover crops to decompose. It’s also important to get to your cover crops before they go to seed, since you don’t want them sprouting up among other crops.

Cover crops can be mowed short and left to decompose in the field, or turned over into the soil. The rich, organic matter that you’ve been growing all winter will now be returned to feed the soil. And you’ll be ready to start planting spring crops! 

Sources for Additional Information

Cover Crop (340) in Organic Systems: Oregon Implementation Guide, NRCS

Cover Crops for Home Gardens, Oregon State University

Getting Started with Winter Cover Crops, Sky Nursery

Try these low-maintenance cover crops to boost soil over winter, OregonLive.com