By Sally McCabe, PHS Associate Director of Community Education
Let’s face it — summer is unofficially over, and all the newbies and amateur gardeners finished planting crops months ago. But what the pros know is that it's time to plan for fall harvest, rip out all the waning summer vegetables, and go crazy filling in all the spaces with cover crops.
What are Cover Crops?
Cover crops are exactly what the name says: crops that cover. They cover the ground with lush growth in all the nooks and crannies where nothing else is growing. But the difference between these and your normal fall plantings is this: we don't expect to harvest these to eat, sell, or give away. These are meant to stay in all winter, covering the ground as mulch and delivering several useful benefits.
Why Use Cover Crops?
If cover crops do all this, how come so few people use them? Many gardeners don’t want to admit that the summer is over, and all those green tomatoes aren’t going to miraculously turn red in the garden by the time frost hits. Most city dwellers don't have acres of available land, so we jealously guard every square inch, gardening intensively to get the most out of our limited space. It takes a shift in thinking to know when to cut our losses when we see diminishing returns on our summer crops. There are lots of compromises we can make along the way to make cover cropping fit our gardening style, including filling every available space in September and October, even between existing plants, while you're waiting for them to freeze or otherwise give up the ghost of new produce.
What Can Cover Crops Do for Your Garden?
Cover crops are very effective at preventing soil erosion and loss of valuable topsoil by protecting it from wind and rain. They also compete with weeds for sunlight, water, and nutrients -- reducing weed growth, while also trapping and holding excess nutrients. Cover crops add organic matter to your soil, which improves structure and soil fertility, and they attract beneficial insects, reducing the need for chemical pesticides. Some types of cover crops (in the legume or bean family) can even pull nitrogen from the air and fix it in the soil for upcoming crops.
