Winter rye
Secale cereale
also called cereal rye, grain rye
The toughest cover crop in the book — germinates in cold soil, roots deep through winter, and holds a bare bed against every kind of weather.
- Type
- Grass · Grown as an annual
- Botanical family
- Mixed / other
- Foliage color
- Green
- Sunlight
- Full sun
- Watering
- Low
- Soil
- Almost anything, including poor and acid ground
- Feeding
- Leafy greens & lawns
- Frost tolerant
- Yes
- Cool-season crop
- Yes — takes a second fall window
- Sow direct
- 35 days before the last spring frost
- First harvest
- 120 days after the last spring frost
- Harvest ends
- 21 days before the first fall frost
- Plant spacing
- 3.9 in
- In-row spacing
- 1.2 in
- Between rows
- 7.1 in
- Square-foot density
- 16 per square
- Sow depth
- 1.2 in
- Root system
- A dense fibrous mat
- Working depth
- 24 in–5 ft
- Can reach
- 6.5 ft down where the soil allows
- Spread
- 8–16 in across, about 1–2× the width of the plant
- Shallowest pot
- 12 in of soil
Thousands of fine roots knit the top of the soil into a turf, which is what holds a bank together and what makes an established clump so hard to lift. Prairie grasses send a few roots far below the mat as well.
Sown as a cover crop it is grown for the roots rather than the grain: a single plant makes hundreds of kilometres of fine root that opens a compacted bed and holds the winter’s nitrogen where the next crop can reach it.
Figures recorded for Winter rye itself. Roots follow the soil either way: a compacted pan, a high water table or heavy clay stops them well short of any of it, and deep open ground lets them go further.
- When
- About 120 days from an autumn sowing, ripening the following midsummer — or cut green in spring as a cover crop, which is what most gardeners grow it for.
- What to look for
- As a grain: straw-colored stems and hard grain in the head. As a cover crop: cut at flowering, when the anthers show, which is when it stops regrowing and gives the most biomass.
- How to harvest
- For grain, cut, sheaf, cure and thresh. For a cover crop, mow or scythe at flowering and leave the residue on the surface as a mulch, or turn it in shallowly.
- How often
- One harvest either way.
- Storing the crop
- Store dry grain airtight. Rye residue releases weed-suppressing compounds for two or three weeks after cutting, so leave that gap before sowing small seed of your own into it.
- Aphids Small sap-sucking insects — greenfly, blackfly — that cluster on soft new growth and excrete sticky honeydew. Squash by hand, hose off with water, and encourage ladybirds and lacewings.
- Leaf spot Brown or black spots that spread and merge in wet weather, sometimes with yellow halos. Pick off affected leaves, clear fallen ones, and water at the base.
- Rust Orange-brown powdery pustules on leaf undersides, weakening the plant over the season. Remove affected leaves, avoid overhead watering, and clear all debris in autumn.
Beneficial predators that hunt this plant's pests — grow their favourite flowers nearby to recruit them. companion plant
- Aphid midge Aphidoletes aphidimyzaHunts Aphids
A tiny midge whose orange maggots paralyze aphids and drink them dry, twenty or more each. Sold as a greenhouse biological control and resident outdoors wherever there are small nectar flowers and an unsprayed aphid colony to find.
- Assassin bug ReduviidaeHunts Aphids
A patient ambusher with a curved beak it drives into whatever it catches — caterpillars, beetles, bugs, and the occasional bee, so count it a generalist rather than a specialist. It will jab a careless finger too, so admire it and leave it be.
- Big-eyed bug Geocoris spp.Hunts Aphids
A stubby 3 mm bug with enormous wrap-around eyes, working the soil surface and the low foliage for aphids, mites, thrips and insect eggs. It is the main natural check on chinch bugs in a lawn and it is killed outright by insecticide.
- Damsel bug NabidaeHunts Aphids
A slender, mantis-armed bug that grabs aphids, small caterpillars, and thrips in low crops and meadowy edges. Leave a strip of unmown grasses and flowers for it to overwinter in.
- Dragonflies & damselflies OdonataHunts Aphids
Aerial hunters that take mosquitoes, midges and small flies on the wing all day, and whose larvae spend a year or more clearing the same insects from the water. A pond with planted margins and no fish is the way to have them.
- Garden birds PasseriformesHunts Aphids
Both things are true: birds strip your currants and a brood of blue tits takes several thousand caterpillars out of one fruit tree in a fortnight. Net what you must and welcome them everywhere else — a nest box near the apples is worth more than a spray.
- Green lacewing Chrysoperla carneaHunts Aphids
Its bristly larvae — "aphid lions" — impale aphids, mealybugs, thrips, and mite colonies, eating hundreds a week. Adults feed on nectar and pollen from small open flowers and overwinter in hollow stems left standing.
- Hoverfly SyrphidaeHunts Aphids
Bee-mimicking flies whose legless larvae graze aphid colonies clean while the adults pollinate. A ribbon of shallow, nectar-rich flowers kept in bloom all season recruits wave after wave of them.
- Ladybird (lady beetle) CoccinellidaeHunts Aphids
The gardener’s favorite ally: adults and their alligator-shaped larvae each eat thousands of aphids, plus scale, mealybugs, and other soft-bodied sap-suckers. Grow flat, open flowers for the adults and never spray a colony that ladybird larvae are already working.
- Minute pirate bug Orius spp.Hunts Aphids
A pinhead-sized true bug that is the best natural check on thrips, and happily spears aphids, mites, and insect eggs too. It needs pollen when prey is scarce, so keep something flowering nearby.
- Parasitic wasps Braconidae & TrichogrammaHunts Aphids
Tiny, stingless wasps that lay eggs in or on caterpillars, aphids, and moth eggs — the white cocoons riding a hornworm are their calling card, so leave that caterpillar be. Umbel flowers with shallow nectar keep the adults fuelled.
- Praying mantis MantidaeHunts Aphids
A sit-and-wait ambusher that snatches caterpillars, beetles, and anything else that wanders close — friend and foe alike, so count it a mixed blessing. Tall, structured plantings give it perches and egg-case anchors.
- Soldier beetle CantharidaeHunts Aphids
Soft-winged beetles seen mating on flower heads in high summer; adults and larvae both take aphids and soft grubs. Open composite flowers are their landing pads and hunting grounds.
- Spiders AraneaeHunts Aphids
Webs, ambushes, and night patrols make spiders the garden’s steadiest generalist predators, taking whatever flies or crawls past. Mulch, ground cover, and undisturbed corners keep the population dense.
Rye roots release compounds that suppress germinating weed seeds — genuinely useful, but wait two or three weeks after cutting before sowing small seed of your own.
Green-leaved grasses, like this one.
The Cottage Garden Companion — the gardener's herbarium at cottagegardencompanion.com