Narrowleaf Flax Plant Care

Linum strictum L.

Updated · Sources · How we source care data

Linum strictum, commonly known as rigid flax, upright flax, and upright yellow flax, is a species of flax with a rigid stem, from whence it derives its taxonomic name, growing to a height of 10–45 cm. The plant is endemic to the Mediterranean region, as well as native to Sudan, Ethiopia, Eritrea, Croatia, Bosnia and Herzegovina, Montenegro, Crimea, Albania, Portugal, Jordan, Iraq, Iran, Madeira, the Canary Islands, the Transcaucasus, Saudi Arabia (Asir), Bahrain, Qatar, Pakistan, and northwest India.

Water

Every 7–10 days

Light

Full sun to partial shade

Temp

60–80°F

Humidity

40–60%

At a glance

How do you care for Narrowleaf Flax?

Water Narrowleaf Flax every 7–10 days, letting the top layer of soil dry out between waterings, and give it full sun to partial shade. It prefers temperatures of 60–80°F (16–27°C) and 40–60% humidity. Fertilize it every 6 months during the growing season.

Where Is the Narrowleaf Flax Native To?

Native range17 countries

What Is the Narrowleaf Flax?

Narrowleaf Flax (Linum strictum) belongs to the Linaceae family within the Linum genus. Narrowleaf Flax is native to Sudan, Ethiopia, Eritrea, Croatia, Bosnia and Herzegovina, Montenegro, Crimea, Albania, Portugal, Jordan, Iraq, Iran, Madeira, the Canary Islands, the Transcaucasus, Saudi Arabia (Asir), Bahrain, Qatar, Pakistan, and northwest India.

Narrowleaf Flax displays an upright, branching herb growth habit, reaching up to 2 ft tall with a spread of approximately 1.5 ft. Narrowleaf Flax produces delicate five-petaled flowers in shades of blue, pink, or white.

Leaf size: approximately 2 inches.

How Often Should You Water a Narrowleaf Flax?

Linum strictum requires watering every 7–10 days. Allow the top layer of soil to dry between waterings to prevent root rot. Reduce watering frequency during winter when growth slows.

Watering Frequency

Every 7–10 days

Let soil partially dry between waterings

What Light Does the Narrowleaf Flax Need?

Narrowleaf Flax thrives in full sun to partial shade.

Light Requirement

Full sun to partial shade

What Temperature and Humidity Does the Narrowleaf Flax Prefer?

Linum strictum grows best at temperatures of 60–80°F. Narrowleaf Flax prefers humidity levels of 40–60%.

Temperature

60–80°F

Humidity

40–60%

What Soil Mix Works Best for a Narrowleaf Flax?

Well-draining sandy loam with added organic matter. Good drainage is essential for Narrowleaf Flax to prevent waterlogging, which leads to root rot and fungal issues.

How Often Should You Fertilize a Narrowleaf Flax?

Feed Narrowleaf Flax every 6 months during the growing season (spring and summer) with a balanced fertilizer diluted to the strength on the label.

Pause feeding in autumn and winter, when growth slows, and never fertilize dry soil — water first.

Fertilizing

Every 6 months

During the growing season

The PlantoScan app can remind you when to water and when to fertilize each plant.

How Do You Repot a Narrowleaf Flax?

Repot every 1-2 years in early spring. Choose a pot one size larger than the current container, and ensure it has drainage holes to allow excess water to escape.

How Do You Propagate a Narrowleaf Flax?

Narrowleaf Flax can be propagated through seeds, division of clumps. Similar propagation techniques also apply to pale flax plant care, which shares the same genus.

Is the Narrowleaf Flax Toxic to Pets and Children?

Pet safety not verified

The ASPCA does not list Narrowleaf Flax, so we can't confirm whether it is safe for cats and dogs. Keep pets from chewing it as a precaution.

This is a general caution, not veterinary or medical advice. If your pet ate a plant, contact your vet or animal poison control.

See all plants toxic to cats and plants toxic to dogs.

What Pests and Diseases Affect the Narrowleaf Flax?

Narrowleaf Flax is susceptible to aphids, spider mites, whiteflies. Inspect the foliage regularly, especially along leaf undersides and stems. Treat infestations promptly with insecticidal soap or neem oil to prevent spread.

Yellow leaves, brown tips or drooping? See common plant problems and how to fix them.

What USDA Hardiness Zone Does the Narrowleaf Flax Need?

Narrowleaf Flax grows outdoors in USDA Zone 13a. It survives winters down to planting zone 13a. Narrowleaf Flax is native to Sudan, Ethiopia, Eritrea, Croatia, Bosnia and Herzegovina, Montenegro, Crimea, Albania, Portugal, Jordan, Iraq, Iran, Madeira, the Canary Islands, the Transcaucasus, Saudi Arabia (Asir), Bahrain, Qatar, Pakistan, and northwest India. In cooler regions, grow Narrowleaf Flax as a houseplant or bring it indoors before the first frost.

Hardiness Zone

Zone 13a

Keep exploring plants

Narrowleaf Flax is one of many species covered in the complete plant care and identification guide, which groups plants by genus, attribute, and popularity.

It belongs to the Linum genus — compare its care with other Linum species on PlantoScan.

Linum is part of the Linaceae plant family — browse all Linaceae genera and species.

Narrowleaf Flax thrives in bright light and direct sun — see other bright-light plants.

More Linum Species

Other Linum species in PlantoScan's care catalogue share similar watering, light, and soil preferences:

Sources

  • Scientific name & taxonomy: Linum strictum L., family Linaceae (first published in Sp. Pl. : 279 (1753)) — World Flora Online record, IPNI name record.
  • Pet toxicity: Pet safety not verified: the ASPCA does not list Narrowleaf Flax, so we can't confirm whether it is safe for cats and dogs. Checked against the ASPCA plant list; any other toxicity note on this page comes from PlantoScan's plant database.
  • Hardiness zone: USDA Zone 13a, calculated from the plant's minimum temperature.
  • Care values(watering, light, temperature, humidity, soil, fertilizing): PlantoScan's plant database, filtered by automatic plausibility checks — values that fail them are hidden. How we source and check plant data.

Spotted a mistake? Email info@upvision.media with the page link — we check and correct reported errors.

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