annual

Scarlet Flax

Linum grandiflorum

The Story

Plant Bio

Linum grandiflorum, native to North Africa, is a slender, upright herbaceous annual that develops branching stems lined with small, grey-green waxy leaves. The species thrives in hot, dry conditions and requires exceptionally well-drained soil to prevent root rot.

This species is distinguished by its loose terminal clusters of saucer-shaped, deep scarlet flowers that open in full sun and feature contrasting light blue pollen on the stamens. Individual blooms last only a day, but the plant produces a continuous succession of flowers from late spring through autumn.

Uses & Benefits:

Provides a vibrant display of brilliant red flowers over a long season in sunny borders and meadows.

Highly drought-tolerant and low-maintenance once established, making it ideal for dry, sandy soils.

Attracts bees, beneficial insects, and generalist pollinators to the garden.

Essentials

At a Glance

Plant Type

Annual

Height

24"

Width

12"

Light

Full Sun

Zones

4, 5, 6, 7, 8, 9, 10

Water

Low

Humidity

Moderate

Lifespan

Annual

Native To

North Africa (Algeria)

Toxicity

Low severity

Bloom period

Late spring – Autumn

In flower about 7 months of the year

Planting

How to Grow

Select a planting site in full sun with light, sandy, or loamy soil that drains rapidly.
Sow seeds directly onto the soil surface after the last spring frost, pressing them lightly into the earth as they require light to germinate.
Water sparingly to keep the soil lightly moist until germination occurs, then reduce watering to allow the soil to dry between applications.
Thin seedlings to six inches apart to allow adequate air circulation and prevent overcrowding.

Pro Tip

Avoid nitrogen-rich fertilizers and heavy watering, as excess nutrients and moisture cause the slender stems to become weak, floppy, and highly susceptible to lodging.

Keep It Thriving

Care Guide

Do

Sow seeds directly in their permanent garden position to prevent transplant shock.
Deadhead regularly or shear the plant back by half mid-season to encourage a second flush of blooms.
Ensure the planting site has excellent drainage to prevent winter wet failure.

Don't

Do not over-fertilize, as excess nitrogen leads to leggy, weak growth and fewer flowers.
Do not plant in heavy clay or waterlogged soils where root rot is guaranteed.
Do not overwater once established, as the plant is highly drought-tolerant.

Seasonal Care Calendar

Task	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Deadhead
Fertilize
Pest Check
Plant

Watch Out For

Pests & Diseases

Common Pests

Common Diseases

In the Garden

Landscape Uses & Companions

Landscape Uses

Meadow plantingsCottage gardensMixed bordersRock gardensGravel gardens

Companion Plants

Eschscholzia californica Centaurea cyanus Lobularia maritima

Multiply

Propagation Methods

Good to Know

Common Questions

Scarlet Flax questions

What zones can Scarlet Flax grow in?

Scarlet Flax is hardy in USDA Zones 4–10. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.

When does Scarlet Flax bloom?

Scarlet Flax typically blooms in late spring through autumn. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.

Does Scarlet Flax need full sun?

Scarlet Flax does best in full sun (6+ hours).

Is Scarlet Flax drought tolerant?

Yes — once established (usually after the first full season), Scarlet Flax handles dry spells with minimal watering. Water deeply its first year to build the root system that makes that possible.