Growing Scarlet Flax: A Complete Profile

By Growing Home Greens Team · August 20, 2026

Scarlet flax is a wispy annual whose individual flowers last a single day. The plant compensates by producing a great many of them.

Sow it thickly or not at all

A single scarlet flax plant looks like a weed with a red flower on it. Sown as a block it reads as a drift of colour, because the fine stems disappear at a distance and the flowers do not. Four to the square foot is the minimum that works.

It reaches 12 to 18 inches. NC State Extension does not publish a height for the species, so that figure comes from the seed trade rather than an extension service, which is worth knowing when you plan around it.

Full sun, poor soil, no fuss

Zones 4 through 9, full sun to partial shade, and it becomes strikingly drought tolerant once established. Rich soil makes it flop. Seed goes in about an eighth of an inch deep after the last frost.

Not the flax that makes linen

Linum grandiflorum is the ornamental. Linum usitatissimum is the fibre and linseed crop, taller, blue-flowered, and grown for entirely different reasons. The seed of the ornamental is not what you would use in the kitchen.

Source: NC State Extension Gardener Plant Toolbox, Linum grandiflorum.

Companion planting guide for Scarlet Flax · Find your planting dates

Typically viable in USDA zones 4-9. Not sure your zone? Look it up by ZIP code.

Method: Direct sow: Direct-sow outside. Scarlet Flax doesn't transplant well, or doesn't need the extra time indoors.

See exact start-indoors, direct-sow, and harvest dates for your zone →

How many Scarlet Flax plants fit per square foot?

Spacing: 4 per square foot (square-foot-gardening spacing). Mature height: 1-1.5 ft.

Where to buy scarlet flax seeds

• Botanical Interests
• True Leaf Market
• Burpee
• High Mowing Organic Seeds

As an Amazon Associate we earn from qualifying purchases. Some links on this page also go to other retailers we may earn a commission from as an affiliate, at no extra cost to you. We only recommend products with a genuine consensus of positive, independent reviews. See the sources cited on each item.

See it growing

Search YouTube for "growing scarlet flax" videos → (a live search, not a hand-picked video; results vary and aren't vetted by us)

Pin this for later

Growing Scarlet Flax: Fine wiry stems and flowers that open in the morning and drop the same day, replaced the next.

Save to Pinterest