How to Grow Cover Crops
Cover crops are a great way to restore your soil after a successful harvest. However, the whole process can be a bit overwhelming when just starting out. Here is a simple guide to get you started with cover crops.
If you’re looking for an all-natural way to protect your garden soil, improve its fertility, and prevent weeds from establishing, then you should add cover crops.
This easy cultivation strategy offers plenty of benefits but can feel overwhelming when you’re just beginning. Which plants are best for cover crops, and when should you sow them?
Here is a beginner’s guide that will teach you everything you need to know to start planting cover crops.
By simple definition, a cover crop is a crop you plant without any intention of harvesting it. Their primary function is to protect the soil’s surface when it’s not growing something else. However, cover crops also give the soil a chance to recover and rebuild its nutrient stores.
There are many reasons to consider planting a cover crop. Below are a few of the most important benefits.
There are three basic types of cover crops to choose from: grains, legumes, and broadleaves.
Grains
These crops grow quickly and build extensive root systems that break up compacted soil. Most are cold-hardy, so farmers can plant them in the fall for “harvesting” in the spring.
Common examples: annual grasses, rye, wheat, oats
Legumes
Commonly known as nitrogen fixers, legumes can produce up to 300 pounds of nitrogen per planted acre to give the next generation of crops a nutritional boost.
Common examples: peas, clover, vetch, soybeans
Broadleaves
These plants germinate quickly and produce big leaves that shade out weeds. Some, like buckwheat, help build up phosphorus, while others break up the soil with large taproots.
Common examples: mustard, buckwheat, alyssum
Sometimes it makes sense to plant a single cover crop over your empty garden bed. In other cases, it’s better to plant multiple species in one spot so the soil gets the full range of benefits. Once you know what your soil needs, you will be able to determine how many cover crops are needed to get the job done.
As a general rule, it’s best to plant cover crops soon after you pull a harvest from a garden bed to minimize the time the soil stays bare. For cold-hardy crops meant to survive the winter, plant them at least one month before the expected first frost date.
Cover crops are almost always seeded directly into the ground. Start by tilling up the soil in the empty bed through the top four inches to remove any remaining vegetation. Smooth the ground with a hand rake until the surface is even. You can scatter the seed over the top by hand or use a seed spreader for larger spaces. Pay attention to the optimal application rate specified on the package.
Use the same rake to cover the seeds with soil. Some varieties, such as rye, require light to germinate and need to stay close to the surface. Others, like most legumes, need a deeper planting for germination.
Ensure the bed stays moist until you see signs of germination. This might require irrigation, but temperatures are often cool enough by the fall for the soil to remain wet after a heavy rain.
After planting, your cover crop should grow vigorously throughout the fall before becoming dormant during the winter. The crop should recover and pick up steam again by early spring.
The best time to deal with mature cover crops is a few weeks before spring planting. Ideally, this should be while the plant is flowering. Cover crops are the easiest to kill when in bloom, and they will break down fast without the risk of spreading weed seeds.
Cut the crop down by hand or with a mower, letting it fall onto the bed to decompose in place. You can till it into the soil after one week so that the nutrients become accessible in the ground for the next season’s planting.
It’s also possible to remove the cut cover crop foliage into a compost pile so it breaks down there instead. While this method might make things more organized around your garden, it creates extra work by making you move the compost back to the bed once it’s finished.
There are dozens of plants that make perfect cover crops, so knowing which ones to choose for your garden can be challenging. Here are several essential questions to ask before starting.
Some cover crops, like clover, are easy to break down by hand. Others, like winter rye, will only die from mowing after it’s created a seed head but before these seeds are released. Have a plan in place for how you’ll kill off your crop so you don’t accidentally release new weeds into your garden.
All cover crops take different amounts of time to mature. Pay attention to your timing in the growing season to ensure you plant a variety that will have time to get large before you cut it down.
Base your cover crop decision around what you plan to plant right after it. For example, heavy feeder crops like tomatoes will love following a nitrogen fixer like legumes, while winter rye residue releases chemicals that may prevent kale and broccoli seeds from sprouting.
Cover crops offer the opportunity to improve your garden soil naturally. Take time to do it right, and your off-season planting will ensure your garden gets better every year.