Flax

Sowing: Flax is direct-sown outdoors after the last frost, its seed barely covered to a depth of about 1/8 to 1 1/2 inches; it germinates within a few weeks and is thinned to stand a few inches apart. Because the plant resents root disturbance it is rarely transplanted, though it can be started indoors in peat pots and hardened off carefully when direct-sowing is not possible.

Site and care: Flax wants full sun and well-drained soil across a wide pH range from acid to alkaline; it tolerates drought, poor soil and rocky ground once established, but heavy clay encourages shallow rooting that leaves plants vulnerable in cold weather. Avoid rich soil or added fertilizer, which favors leaf growth over flowering, and keep weeds down for the first few weeks after germination, when seedlings are too small to compete on their own; growing flax in a three- to four-year rotation with small grains is also recommended. Where flowering continues over a long season, cutting the stems back by about half after the main bloom encourages a further flush and keeps plants from becoming sparse.

Cutworms and grasshoppers are occasional pests of flax. Fusarium rust and other fungal diseases can also affect the crop, and rotating flax with small grains over a three- to four-year cycle helps keep these fungal problems in check.

Harvest: Fiber flax is cut before its seed matures, about 90 to 100 days after sowing, while flax grown for oilseed is left longer, harvested 90 to 120 days after sowing once the capsules have ripened in fall. Traditionally, plants were pulled by hand, roots and all, clearing the field for the next crop; larger plantings require a mechanical puller or grubber.

Processing: After pulling, the stems are field-retted for one to three weeks, a natural exposure process that loosens the fibers from the bark and woody core so they can be separated, dried and spun into yarn for weaving into linen.

Culinary: Flaxseed is valued for its omega-3 fatty acids, fiber and lignans; it is ground into meal for smoothies, cereals and baked goods, used as an egg substitute in vegan cooking, and pressed for an oil that is used in salad dressings and as a supplement rather than for cooking, given its low smoke point. The cake remaining after oil pressing is fed to livestock as a protein supplement, and flaxseed meal is also used in some dog food.

Fiber: The stem fibers are spun into linen, traditionally used for bed sheets, underclothing and table linen; long line wet-spun flax continues to supply high-end fashion and outdoor sportswear, while coarser tow fiber is used in geotextiles, weed-suppressing horticultural fabric, rope, paper, and as a fiberglass substitute in composite materials.

Industrial: Linseed oil pressed from the seed is used in wood finishing, paints, varnishes and linoleum.

Ornamental: Flax is also grown for its showy blue flowers, occasionally as a cut flower.

Flax is known only in cultivation and appears to have been domesticated a single time from the wild pale flax, Linum bienne. Its use as a fiber crop reaches back some 30,000 years, linen cloth has been recovered from Egyptian tombs, and the crop was common in early America; it has since naturalized across Europe and parts of North America beyond its original range.