GrowJoy’s Guide to Growing Fall Cover Crops in Your Home Garden

Cover crops growing in the garden

Eyeing your dormant garden and wondering about growing fall cover crops? We’ve got the full guide to growing these beneficial crops! Farmers have long used cover crops to revitalize spent soil. And home gardeners can get just as much benefit from them. In the past, seed for cover crop was only available in big sacks. But that has changed. Meaning that the cultivation of cover crops something worth considering even if your garden is small. Here we’ll explain why growing fall cover crops is one of the best things you can do for your soil, and we’ll help you choose the best cover crop for you. You just have to follow the directions that come with the seeds and then get excited about the harvest you’re going to have after the cover crop has improved your soil’s nutrient levels, structure, stability, drainage, and more.

Why Grow Fall Cover Crops?

Soil literally wears out from having crops repeatedly grown in it. They leach the nutrients out until there is not much left. The nutrients in veggies are a major reason why they’re so good for you, but the soil that produced them also needs to be replenished. Fertilizer is not the ideal solution, especially long-term. For one thing, it gets washed away. But more importantly, the growing process undermines soil structure and stability, and fertilizer can do nothing to fix that. By planting cover crops you will be able to restore both the nutrient content of your soil and also its structure and stability.

Other benefits of growing fall cover crops include improved soil drainage and aeration, decreased erosion, suppression of weeds, pest control, and reduced susceptibility to soil disease. Some cover crops break up compacted soil and attract beneficial insects. Cover crops also add valuable organic matter to your soil, similar to the enhancement you get from applying compost. You’ll find that the veggies you plant in the future will grow bigger, taste better, and produce higher yields.

Growing Fall Cover Crops: How it Works

After your summer harvest, instead of planting new veggies for the fall growing season, instead sow a cover crop for the purpose of revitalizing the soil. You then mow it down at the correct time. Or, in the case of radishes, let them freeze over the winter, after which time they decompose under the ground. With new rich, decomposed organic matter in your soil, it will be in terrific shape by the time you’re ready for your next planting.

Varieties of Cover Crops

There are a number of different varieties of cover crops. Five that are a good choice to plant in fall are: Sweet Clover, Hairy Vetch, Groundhog Radish, NitroRadish, and Annual Rye

Natural Nutrient Adjustment 

Do you know your soil’s pH? You’ve probably heard that doing a soil test is easy and inexpensive these days, and is a vital step to a healthy garden. It will also help you determine what cover crop to choose. Because if your soil is lacking in nitrogen or potassium, cover crops can increase the amount of these key nutrients.

Through the use of cover crops, you can actually grow your own nitrogen. Sweet Clover, Hairy Vetch, Groundhog Radish, and NitroRadish will all increase the amount of nitrogen in your soil. These actually work far better than fertilizer to fix the nitrogen and make it available to whatever crops you’ll be planting in the next growing season. By the way, both Groundhog Radish and NitroRadish grow well in drought conditions.

Annual Rye works differently. Known as a nitrogen scavenger, it reduces nitrogen but increases potassium. So it’s a great choice if you want to shift the nutrient balance in your soil in the direction of more potassium (K) and less nitrogen (N). Rye also contains natural toxins that will suppress weeds and may even keep the pests away the next time you grow a crop. Farmers have long known that you won’t find nematodes in a field where rye grass has been growing.

Be sure to at least do a simple NPK soil test. That way you’ll know exactly where your soil stands in terms of three essential nutrients: nitrogen, phosphorus, and potassium.

Breaking Up Compacted Soil and Hardpan

Another special use of cover crops is to break up compacted soil, hardpan, and the like. Two radish varieties, Groundhog Radish or NitroRadish, both do a great job of this. Sweet Clover is also effective for this purpose. Each of these cover crops will improve soil drainage and aeration, whether your soil is compacted or not. That’s because when they decompose, the roots leave large holes in the ground that extend down as far as two feet and deeper. For this reason, these kinds of radishes are sometimes referred to as bio-drills.

Tips and Advice for Growing Cover Crops

  • Of all of the cover crops we’ve mentioned here, rye is the easiest to grow; sweet clover is the most difficult.
  • In the northeastern United States, opt for ryegrass first as a garden cover crop. As the plant scientists at Cornell University explain, it is a vigorous grower with an extensive root system that occupies the same root zone as the garden plants.
  • Think about when you would next like to use your garden. With most cover crops, you’ll be ready to go the following spring. But if you plant Hairy Vetch it may not be ready to cut until the following June. And then you have to allow time for it to decompose. In other words, your ground will remain fallow for one year.
  • Master gardener Diana Roberts suggests that you trade off cover crops on one side of your garden for vegetable crops every other year. Meaning you would change the cover crops when necessary and rotate vegetable crops from one side to the other. In this way, she explains, you won’t have to forego a garden for one whole year. As soon as you harvest your vegetable crop, plant a cover crop. Through this technique she has eliminated the need for fertilizer.

Moving Forward With Cover Crops

Here’s a chart with the information you’ll need to make a decision on which cover crop will be best for you. 

Comparison of Four Fall Green Manure Cover Crops

Planting Time
Notable Features
Time Needed Before Mowing
Growing Tips

Annual Ryegrass Seed

End of August is ideal

Removes excess nitrogen; stabilizes soil and improves its structure, reduces erosion, controls nematodes and strongly suppresses weeds.

4–6 weeks, or wait until spring

Easiest cover crop to establish but needs to be kept moist. Will grow all right in compacted soil, and in other difficult conditions.

Groundhog Radish Seed

Late summer;early fall

Increases nitrogen; suppresses weeds,breaks up compacted soil.

No mowing necessary

Radishes are low maintenance, but roll ground after seeding to ensure good seed-to-soil contact.

Hairy Vetch Seed

Late summer;early fall

Increases nitrogen even more than peas; suppresses weeds, controls erosion, stabilizes soil, reduces surface hardness.

When it flowers, which may not be until the following June

Can be combined with rye for more biomass. Does not do well in compacted soil. Does do well inclay soil; slow to establish.

Yellow Blossom Sweet Clover Seed


Increases nitrogen;breaks up compacted soil; attracts beneficial insects; helps attract bees.

Leave it and then cut it down in the spring

Can grow in wet, poorly drained, alkaline, salty and low-fertility soils.Grows well in clay soils.

Happy gardening!

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