Flax

Flax (Linum usitatissimum), also called linseed, is a short-lived annual with pale blue flowers on slender stems. Its stems are used to make linen and its seeds are pressed into linseed oil. Flax seed is also eaten in food products and used as animal feed.

When and how to sow. Sow flax seed outdoors in spring, after the danger of hard frosts has passed. Plant it about ½ to 1½ inches (1.3 to 3.8 cm) deep. Choose a spot in full sun, since flax does best in full sun and cannot grow in shade. Keep fertilizer away from the seed, because seedlings are sensitive to too much nitrogen. Flax prefers moist, well-drained soil that ranges from mildly acid to mildly alkaline.

Water and soil. Flax tolerates drought and dry or rocky soil, but clay soil can make its roots grow shallowly.

Pruning. Where flax is grown as a perennial, cutting the stems back by half after flowering keeps plants from becoming leggy.

Pests and weeds. Cutworms and grasshoppers can be occasional pests. Flax competes poorly with weeds compared with cereal crops, and broadleaf weed control options are limited. In field trials, no pathogens or insect pests were observed.

The brown to copper seed capsules appear in fall. Each capsule holds 10 flattened seeds.

For people. A general plant database rates flax as medium severity for people, and says it is toxic only when large quantities are eaten. The database lists seeds, leaves and stems among the affected parts. Linseed oil may cause skin irritation on contact.