Best Cover Crops for Overwintering

By October, a lot of growers figure the cover crop window has closed. For some species, it has. But cereal rye and a few other winter-hardy options can still go in and put down roots before the ground freezes. That gets you erosion protection through winter and a head start on growth when fields green up in spring.

Winter-Hardy Options: Cereal Rye, Hairy Vetch, and Winter Soil Armor

Cereal rye is the go-to for late planting. Hazlet cereal rye can germinate in soil as cold as 34°F, so it's often the best fit when you're seeding late.

Green Cover's Winter Warrior hairy vetch is grown in Montana, South Dakota, and Canada, which makes it one of the most cold-tolerant vetches you can plant. It needs warmer soil to germinate than rye does, so get it in earlier. With a full stand and a later corn planting date, it can produce over 200 lbs of nitrogen per acre.

For erosion control, Winter Soil Armor combines cereal rye, hairy vetch, and rapeseed. Plant it 4–6 weeks before your average frost date, and no later than mid-to-late October.

What You Get in the Spring

When fields green up, overwintering covers get back to work. Living roots hold soil in place, build soil structure, and help compete with early weed flushes. Hairy vetch adds nitrogen, but it grows slowly in early spring and puts on most of its growth later. The longer you let it grow before termination, the more nitrogen you'll get, so plan termination around your corn or soybean planting.

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