Perennial Flax

Perennial flax (Linum perenne) is a slender, spreading perennial native to the Alps and eastern Europe, producing a long succession of sky-blue flowers on wiry stems with needle-like leaves. Reaching 40–60 cm in height, it creates an airy, meadow-like effect in the garden. It thrives in light, well-drained soils in full sun but tolerates partial shade. An heirloom species that self-seeds freely once established.

Growing

Surface-sow seeds indoors under light at 10–15 °C; seeds require light for germination so press onto the surface without covering. Start 6 weeks before transplanting out. Maintain consistent moisture during germination, which takes 10–30 days. Transplant outdoors once nights remain reliably above 5 °C and frost risk has passed, spacing plants 10–15 cm apart. Alternatively, direct-sow onto a prepared seedbed in late summer or autumn; seed lightly into raked, firmed soil.

Care

Water moderately during establishment; once rooted, perennial flax is drought-tolerant and needs little supplemental irrigation in normal rainfall conditions. Avoid heavy or waterlogged soils. No feeding is necessary in poor to average soils — rich soil promotes leafy growth at the expense of flowers. Deadhead spent blooms to extend the flowering period, or leave seedheads to allow self-seeding. Cut back lightly after the main flush of bloom to encourage a second flush.

Harvest

Flowers open over an extended period once the plant reaches full size, typically from late spring through summer. For cut flowers, harvest stems when two or three buds on each stem have just opened. Individual flowers are short-lived but new buds open daily. Allow some seedheads to ripen and self-sow if naturalising is desired.

In the kitchen

Perennial flax is primarily an ornamental plant. The flowers are edible and can be scattered over salads or used as a garnish. Linseed (the seed of the related Linum usitatissimum) is the culinary flax; seeds of Linum perenne are not typically used as food.

Storing

Cut stems can be kept in cool water for 1–2 days. Dried seedheads can be stored in a cool, dry place for floral arrangements. Saved seed should be dried thoroughly and stored in a sealed paper envelope in a cool, dark location; viability lasts 2–3 years.