Fall Cover Crops by Zone: What to Plant Now

September 22, 2026

Cover Crop Planting Dates by Zone: The Quick Answer

Empty beds lose nitrogen and structure over winter if they sit bare. The sow-by date is the variable that matters most, and it moves fast as you go north. Use this table to find your zone, then read the section below for the details on timing and termination.

USDA Zone	Cover Crop	Sow By	Terminate
3b-4b	Winter rye	Sept 20	Mow or till mid-May
5a-5b	Winter rye or oats	Sept 25-Oct 5	Till 2-3 weeks before planting
6a-6b	Winter rye or crimson clover	Oct 1-15	Till 2-3 weeks before planting
7a-7b	Crimson clover, Austrian winter peas	Oct 1-20	Cut at first bloom, spring
8a-8b	Crimson clover, daikon radish	Oct 15-Nov 5	Radish winterkills; clover cut at bloom
9a-9b	Austrian winter peas, daikon radish	Nov 1-15	Radish winterkills; peas cut at bloom
10a-11a	Frost-free: skip dormancy-dependent covers	N/A	Succession-plant instead

Frost date and soil temperature at sowing determine germination and winter survival more reliably than the calendar month, so treat these windows as starting points and check your local frost date before you commit a bed.

Winter Rye: The Cold-Zone Standard (Zones 3-6)

Winter rye goes in the ground by September 20 in Zone 3b-4b and by early October in Zone 5a-6b, as soon as the previous crop clears the bed. It’s the only cover crop reliable enough to establish before hard frost in these zones and still put on enough top growth to survive under snow.

If you want the full zone-by-zone planting calendar for what goes into these beds come spring, our regional guides are collected at the GardeningByZone book library.

Seed winter rye at 3 to 4 pounds per 1,000 square feet, raked in to a quarter inch and watered if the top inch of soil is dry. Soil temperature at seeding should still read above 40°F; below that, germination slows enough that the planting misses its establishment window before the ground locks up. Rye germinates in 5 to 10 days at that temperature and keeps growing slowly through fall, which is what separates it from oats or buckwheat: neither survives a hard freeze, so both are the wrong call once you’re inside a Zone 6 first-frost window. Check your bed’s expected first frost against first frost dates by zone before finalizing a sow date, since a week’s difference between a coastal and inland Zone 6a garden can be the gap between a rye stand that establishes and one that doesn’t.

Terminate rye by mowing or tilling 2 to 3 weeks ahead of spring planting, once it reaches 12 to 18 inches. Wait longer and the stand sets seed, which turns next year’s bed into a rye patch instead of a vegetable bed.

Warm-Zone Cover Crops: Crimson Clover and Winter Peas (Zones 7-9b)

Zone 7a-7b and warmer skip winter rye’s urgency. Sow crimson clover or Austrian winter peas from October 1 through early November, with the later end of that window holding for Zone 8b, where soil stays warm enough for germination into the first week of November most years.

Crimson clover fixes nitrogen at a higher rate than rye and adds a spring bloom that pulls in early pollinators, useful if the bed sits next to anything already flowering. Austrian winter peas do the same nitrogen work with a faster spring breakdown once cut, which matters if the bed is going into an early transplant like tomatoes. Pair either with daikon radish in Zone 8a-9b: the radish taproot breaks up compaction through fall, then winterkills on its own once temperatures drop into the low 20s, leaving a loosened bed with no spring termination step required for that portion of the mix.

Garlic growers with an empty bed slated for cloves in late October or November should hold off on a full cover crop there. Broadcast crimson clover on the rest of the plot instead and save that bed for the garlic planting window, since the two crops are competing for the same square footage on the same calendar.

How to Sow Cover Crops on Empty Beds

Clear old crop residue and roots before broadcasting seed; a cover crop sown over an intact pepper or tomato root mass germinates unevenly and competes with decomposition instead of bare soil. Rake the bed to break up the surface crust, broadcast at the rate listed for your crop, then rake again lightly to bury seed a quarter to half inch deep. Water immediately after seeding and again every 2 to 3 days until germination if fall rain hasn’t arrived yet; cover crop seed dries out and fails to establish at roughly the same rate as any other direct-sown seed.

Don’t fertilize at sowing. The whole point of a legume cover crop is nitrogen fixation from the soil and air, and feeding the bed ahead of that process wastes the input and skips the reason you planted the cover in the first place.

Why Bother: Soil Benefits Without the Triad Trap

Cover crops hold soil structure through winter rain and cut spring weed pressure by outcompeting whatever would otherwise germinate first on bare ground. Legume varieties add fixed nitrogen the following crop draws on directly, which is the difference between a spring bed that needs a full fertilizer program and one that needs a lighter top-up. Neither benefit requires the other to be worth the seed cost. A single fall sowing, on a bed that would otherwise sit empty until April, pays for itself in the spring till alone.

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