How to Plant and Grow Flax

This perennial with sky-blue flowers blooms through dry and hot summers.

Don’t let the frothy beauty of this tufted plant fool you. With its airy stems and pretty sky-blue flowers, flax has a delicate appearance but in fact, it is quite tough and stands up to drought and heat with ease. Perennial flax (Linum perenne) begins its profuse blooming in early summer and blooms right through the dog days of summer in many areas, adding a cool wash of color to any landscape. Each five-petal blue flower lasts only one day: opening in the morning but dropping petals by late afternoon.

Flax Overview

Genus Name Linum perenne
Common Name Flax
Plant Type Perennial
Light Part Sun, Sun
Height 1 to 3 feet
Width 9 to 18 inches
Flower Color Blue
Foliage Color Blue/Green
Season Features Summer Bloom
Special Features Attracts Birds, Good for Containers, Low Maintenance
Zones 5, 6, 7, 8
Propagation Seed
Problem Solvers Drought Tolerant, Groundcover, Slope/Erosion Control

Where to Plant Flax

Flax is quite adaptable to site conditions and soil pH but ample sun and light, well-drained soil are musts.

Flax grows as a large carpet of color in its native environments of Europe and Asia. To mimic its native growth habit, plant it in large, generous drifts, which is easy to do because it is grown from seed. Flax is also well-suited to rock gardens, the front of a perennial border, and curbside where it can handle heat and drought.

How and When to Plant Flax

Flax does not like to be transplanted, therefore direct-seeding is recommended. In the early spring, and in warm climates also in the late summer or early fall, scatter the seeds over an area that has been cleared of all weeds and raked. A seed packet containing about 400 seeds covers roughly 80 square feet.

Tamp down the soil so the seeds have soil contact, do not cover them. Water the areas thoroughly but gently so you don’t wash away the seeds. Keep it moist until about four weeks after the seedlings emerge to encourage a strong root system. Do not thin the plants. Some of the plants grown this way may even flower the first year.

Flax Care Tips


Full sun is essential for flax to thrive. In southern locations, partial shade is acceptable.

Soil and Water

The soil needs to be well-drained. Wet feet will kill this plant. Heavy, clay soil causes this perennial to develop shallow roots, which prove challenging to its survival in winter. The pH can be anywhere from slightly acidic to slightly alkaline.

Other than watering until the plants are established, flax does not need supplemental watering.

Temperature and Humidity

Flax can handle winter chill and summer heat as well as moderate humidity,


More is less when it comes to nutrients for flax. Do not add fertilizer or manure. In soil that is too rich, the bloom is reduced.


As the bloom period comes to an end, flax tends to look leggy. At that point, you can trim it back by half its height. This might coax it into sporadically producing additional flowers in the early fall.

Potting and Repotting

Although the visual effect won’t be as striking as the sea of blue from a mass planting, you can grow flax in containers. Use a pot with large drainage holes that is at least 10 inches deep to accommodate the tap root and fill it with well-draining lightweight potting mix. To prevent the pots from toppling over, select short varieties. Unlike flax in the landscape, potted plants need more frequent watering and a moderate amount of slow-release granular fertilizer—once at the beginning at the growing season, and again in midsummer should be sufficient.

Pests and Problems

Flax is generally not bothered by any pests and diseases, and it is deer-resistant.

How to Propagate Flax

If you love this plant with its wiry stems and blue blossoms, keep your fingers crossed—flax happily self-seeds in ideal growing conditions without becoming invasive.

Flax is best propagated from seed as described above.

Types of Flax

Note that New Zealand flax is a flax only in name, it is a different species and botanically not related to flax.

Blue Sapphire Perennial Flax

Linum perenne ‘Blau Saphir' is a cultivar of perennial flax that is cold-hardier than the species but just as drought-tolerant. It grows 12 to 15 inches tall. Zone 3-9 

Wild Blue Flax

This flax, also called prairie flax, is an annual short-lived perennial native to North America. It has blue flowers and grows 18 to 30 inches tall. Zone 3-8 

Flowering Flax

Not all flax is blue—this annual flax variety has scarlet flowers. The species is naturally found in North Africa and southern Europe. It grows 12 to 36 inches tall.

Frequently Asked Questions

  • What is flax used for?

    The tough, fibrous stems of perennial flax were once used to make linen and rope in Europe. Today, linen is made from the stems of several varieties of common flax (Linum usitatissimum).

  • What part of flax is edible?

    The flax variety grown for consumption is common flax (Linum usitatissimum), also called linseed, not Linum perenne (perennial flax). It’s the seeds which are eaten raw or pressed to make oil.

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