How to Sow
You can sow seeds from midsummer through early fall. When all your summer or fall crops have been harvested, prepare the bed by removing any plant debris or tilling it into the soil.
Clear out any stones or large debris and rake the surface of the soil in preparation for sowing.
If you’re planting hairy vetch in an area where legumes haven’t been grown recently, it’s a good idea to inoculate the seeds with the appropriate strain of Rhizobium leguminosarum bacteria before sowing.
After inoculation, if using, sow seeds about half an inch to an inch deep. If you’re sowing in rows or small sections, space them roughly three inches apart.
For larger beds, you can broadcast the seeds evenly over the surface, then rake or press them in lightly to ensure good soil contact.
Water well to ensure even moisture in the top layer of soil. Keep the soil lightly moist. Seeds should sprout in about seven to 10 days.
How to Grow
Hairy vetch grows best in full to partial sun, in well-draining soil with a pH between 5.0 to 7.5, so it’s suitable for use as a cover crop in most backyard vegetable beds.
After germination, there’s no need to thin the seedlings, just allow them to grow freely to form a dense ground cover.
Maintain consistent soil moisture until a hard frost arrives or temperatures reliably remain below 40°F. During this time, trim back any stems that begin to encroach on other parts of the garden.
When cold weather sets in, you can stop watering. Little maintenance is required through winter, so your job is pretty much done until the final frost of spring.
Where to Buy
Hairy vetch seeds are available at all good plant nurseries and online.
If you’d like a recommendation, you can find packets of seeds available at Botanical Interests.
Termination in Spring
As spring arrives and the last frost date approaches, it’s time to deal with your cover crop before planting new crops.
About three weeks before sowing seeds or transplanting seedlings, cut the hairy vetch at the soil line using a hoe or garden shears.
At this point, you have several options for handling the plant residue.
You can leave the clippings in place as a green surface mulch, work them into the soil, or compost them separately.
Whichever method you choose, be sure to incorporate the lower stems and roots into the soil to boost organic matter and nutrient availability.
The ideal time to terminate a cover crop is when it starts flowering but before it sets seed.
