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Linum usitatissimum

common flax

Linaceae

Mediterranean and western Asia, in cultivation worldwide

Attracts Pollinators Container Friendly

SunFull Sun

WaterMedium

Overview

Linum usitatissimum is an annual in the flax family, long grown for its fibre and oil-rich seed. It produces slender, erect stems 12-48 inches (30-120 cm) tall, usually unbranched below and branching only near the top. The narrow, pointed leaves are 0.4-1.2 inches (10-30 mm) long, grey-green, and set alternately along the stem. From June to August the plant bears five-petalled flowers about 0.6-1 inch (15-25 mm) across, typically sky-blue but sometimes white, each opening for a single morning and shedding its petals by afternoon. Round seed capsules follow, each holding up to ten flattened, glossy brown seeds, the linseed of commerce. Fibre flax is grown tall and unbranched for the long stem fibres spun into linen, while seed types are shorter and more branched. Immature capsules and foliage contain cyanogenic compounds. Cultivated for thousands of years, it is not reliably wild but persists as a casual on field edges and waste ground. It needs a single season to grow, flower, and set seed.

Native Range

Derived in cultivation from the wild Linum bienne of the Mediterranean and western Asia, and now grown across temperate regions worldwide. In Britain it occurs as a crop and as a casual escape on disturbed ground.

Suggested Uses

Grown as a field crop for linen fibre and for linseed and flaxseed oil, and on a small scale in cottage and heritage plantings. The blue flowers suit ornamental and pollinator borders for summer colour. Dried stems and capsules are used in crafts and arrangements.

How to Identify

A slender, erect annual with narrow grey-green leaves and five-petalled flowers about 0.6-1 inch (15-25 mm) wide, usually sky-blue. Flowers open in the morning and drop their petals by afternoon. Round capsules hold flat, glossy brown seeds, separating it from the perennial wild flaxes.

Appearance

Size & Dimensions

Height1' - 4'

Width/Spread4" - 10"

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~8 weeks

Summer

Flowers open from June to August, each lasting only a single morning before the petals fall. A field in flower turns blue early in the day and fades by afternoon as new buds open in succession. Bees and hoverflies visit the short-lived flowers for pollen.

Detailed Descriptions

Foliage Description

grey-green

Growing Conditions

Sun Requirements

SunFull Sun

Requires 6-10 hours of direct sunlight daily

• Full Sun: 6+ hours of direct sunlight

• Partial Shade: 3-6 hours of direct sunlight

• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range6.0 - 7.5(Neutral)

357912

Soil Types

loam silt

Drainagewell drained

Water & Climate

Water Needs

Medium

Care & Maintenance

Care Guide

Linum usitatissimum grows in full sun on free-draining, fertile loam of neutral pH. It needs an open, sunny site and even moisture during stem growth, and yields poorly on dry or waterlogged ground. As an annual it is sown directly in spring, broadcast or drilled, and is not transplanted. Fibre crops are sown densely for tall, unbranched stems, while seed crops are spaced wider. The plant matures in roughly 90 to 110 days from sowing to ripe seed. Heavy nitrogen causes soft growth and lodging, and wet harvest weather spoils the fibre and seed.

Pruning

No pruning is carried out on this annual crop. Fibre flax is pulled whole, roots and all, as the lower stem yellows, while seed flax is cut or combined once the capsules ripen. Plants are removed at the end of the season.