A Cover Crop Adventure
What is a cover crop?
Ever heard of a cover crop? Me either, till recently. Growing up in a farming community, you think I would have. So what is a cover crop? According to the Sustainable Agriculture Research and Education (SARE) website "a cover crop is a plant that is used primarily to slow erosion, improve soil health, enhance water availability, smother weeds, help control pests and diseases, increase biodiversity and bring a host of other benefits to your farm."
You're probably thinking, "I don't have a farm, why are you talking about cover crops?"
I'm glad you asked. See that picture of the raised garden bed? I inherited it after moving into our current house. We weren't planning on being here too long. Instead of having to tend and weed it, I covered it with black plastic. It made a great place to put my potted garden.
Well, we have been here a little longer than anticipated. (sigh) That raised bed seemed to be calling my name and asking me to make use of it. So, when I decided to start growing and selling cut flowers, the neglected bed looked like ideal solution.
Pulling back the plastic exposed the soil and one look told me this soil wasn't going to grow anything. Sure, the plastic had done its job of killing any weeds in it; However, it had also killed everything else in the soil. All micro organisms once living there had long since been baked alive. Not only was everything in the soil dead, but the ground was compact. Looking at the soil led me to realize it needed to be revived and without spending an arm and a leg because let's be honest, with three kids I need all my arms and legs.
Enter my trusty old friend Google!!! I found a bunch of different additives to improve soil viability and health. Also things that could be done over the course of two to three years. Patience really isn't my strong suite and I wanted a fix, NOW! My continued search led me to a story about a person that had expanded his garden just before their family had three new kids added to it. If you have kids, you know that means the new expansion was ignored. Thistles slowly started to take over and by the time he could get to it, thistles ruled. To counter the thistles, he planted alfalfa. After a year of growing and harvesting alfalfa, the thistles were down to a manageable amount. Why did planting alfalfa lessen the amount of thistles? As the alfalfa grew it choked out the thistles and also covered the soil, leaving less area for new thistles seeds to take root. He called the alfalfa a cover crop. Intrigued, I did a little more digging.
It turns out that farmers have been doing this for years! Different cover crops result in different benefits. Legumes take nitrogen from the atmosphere and add it to the soil. Beans and clovers are part of the legume family. This might explain why those clover patches in your yard are greener than your grass.
Types of Cover Crops and their uses
Grasses, such as rye, wheat, barley, and oats can be used as cover crops and are great for suppressing weeds, preventing erosion and adding organic matter into the soil.
Brassicas, including mustard, rapeseed, and forage radish, can be used as well.
Radishes have a large taproot that can help break up compacted soil making it easier for following plant roots to access nutrients in the soil.
When picking a cover crop you can grow one that will die off in the winter and can be tilled into the soil the following spring or you can grow a perennial one that you'll have to kill off in the spring three weeks before you want to plant your main crop.
Deciding what cover crop to use
Okay, now that you are overloaded on what cover crops are and can do, back to my raised bed. My thought was to apply the concept of cover crops to my little bed. I now need to find a plant that would break up the compacted soil. It needs grow large enough to have a good amount of greenery to till into the soil and adding some nitrogen to my depleted soil would also be a nice bonus.
I live in St. Anthony, Idaho.
It's cold here.
My growing season is short.
By the time I discovered cover crops and their benefits, it was too late to plant an annual crop that would grow to cover the bed and produce enough greenery to be tilled into the soil. The other issue was finding seed.
While you can plant multiple types of cover crops in the same place, I wanted to stick with one. My first choice was some kind of legume or grass. I could have ordered seed online. However, with it being 2020 and shipping taking a lot longer than normal, knowing my luck it would get here in December?
It was September and it had already frozen once. Remember, I live in St. Anthony, Idaho, winter could be tomorrow or a couple months away. After searching stores in Rexburg with no luck, I found Trost Feed and Seed in St. Anthony. They had red clover seeds!!! They were great at helping me determine the amount of seed needed for my bed.
After procuring seed, it was time to till up the soil and hand broadcast the clover seed. Keeping my kids from tramping down the soil though was easier said than done. My efforts must have been successful, because two weeks after being broadcast there are little green sprouts popping up all over my raised bed. The clover will grow until about April and then be killed off and tilled in. The goal is the clover will improve the soil by adding some green manure and fixing nitrogen in the soil. The large root systems of clover will also help break up the compacted soil.
The craziest thing about this experiment is that by planting what is usually considered a weed I will cut down on the amount of weed seeds that take root between now and next spring. This will lessen the amount of time I have to spend weeding. So planting the "weeds" will actually save me from unwanted weeds and help me from losing soil before I can plant in the spring. It's just like my grandpa used to say, "A weed is just a plant that's growing where you don't want it."
Happy Gardening!