Secale cereale aka Rye

Secale cereale is rye, also called cereal rye or winter rye. It belongs to the grass family, Poaceae. This crop arose through domestication in southern Turkey. Farmers now grow it worldwide, chiefly in temperate regions. It is an annual, though Kew also records a biennial life cycle. It differs from the ryegrasses used for lawns, which belong to Lolium.

Rye grows fast and forms upright tufts or clumps. Garden plants reach 2–4 feet (0.61–1.22 metres) tall. They spread about 0.5–1 foot (0.15–0.30 metres) wide. The stems have a blue-green tint and lack scent. Green leaves are long, narrow, hairless, and papery, with smooth edges. Small green flowers draw little notice on the plant. Their heads can add shape to dried flower displays. The fruit is a small, brown to golden grain called a caryopsis.

Grow rye in full sun and soil that drains well. It suits sand, loam, clay, chalk, and shallow rocky ground. It accepts acid, neutral, or alkaline soil. Moist soil suits it, though it can cope with occasional dryness. Avoid sites that flood; moderate soil fertility gives the best results. The RHS rates its UK hardiness as H5. Plants reach maturity within a year and need little upkeep. Sow seed into a fine, weed-free bed and keep it moist.

Gardeners use rye as a winter cover crop on bare beds. It also suits orchards and permaculture plots. Its roots and dense top growth help reduce wind erosion. The crop shades out weeds and adds organic matter. It also helps retain soil nitrogen through winter. Rye does not fix nitrogen, unlike legumes such as hairy vetch. Gardeners can grow the two together as a cover crop. Cut rye down in spring and dig it into the soil. Leave a few weeks before sowing or planting the next crop.

Farmers also grow rye for forage and edible cereal grain. The supplied species sources do not establish its toxicity status. Serious pest and disease problems are uncommon in cover crops. Young plants may still suffer from slugs, snails, or aphids. Rust, blight, and other fungal diseases can occur. Beyond crop beds, the RHS lists informal gardens and flower borders as suitable settings.