How to Grow Linum
Linum At a Glance
Difficulty
Moderate
Category
Flower
Sun Exposure
Full Sun, Partial Sun
Frost Tolerance
Frost Hardy
Cold Hardiness
Survives to -12°C
Plant Family
Linaceae
Growing Season
Cool Season
Plant Lifecycle
Annual
How to Start It
★ Recommended for beginners
Flax handles light frost, so sow it in early spring, about 1 to 4 weeks before your last frost. Scatter the seeds 0.5 cm deep right where they will flower, since the plant grows one long main root and does not like being moved. They sprout in 10 to 14 days: thin them (pull the extras so each has room) to 10 cm apart.
Each flax flower lasts only a day, but the plant opens fresh ones every morning for weeks. Sow short rows a couple of weeks apart until early summer for a longer show. Let a few plants make seed and they often come back on their own next spring.
When To Start
First chance to plant
30 Days Before Last Frost
Last chance to plant
30 Days Before First Frost
When should you plant Linum?
Your planting dates depend on your local climate. Sign up and add your location to unlock personalized dates.
Your Linum Planting Window
Start planting
May 15, 2026
Last chance
Sep 10, 2026
Your Linum Calendar
Set your location to turn these into exact dates and reminders.
Sow flax outdoors in a sunny spot, again every 2 weeks
1 week before your last frost· every year
Did you water your linum seedlings today? Keep the top of the soil damp until they are up and growing.
About 1 days after you plant it
Time to thin the linum seedlings: snip the extras at soil level so each one has room to grow.
About 24 days after you plant it
Your flax is coming up nicely! Keep the bed weeded so the slim young stems are not crowded.
About 34 days after you plant it
Flower time is close! Water during dry spells to keep the blooms coming.
About 54 days after you plant it
Picking time may be here: check your linum.
About 60 days after you plant it
The Journey Ahead
Linum's Lifecycle
Seedling
Mature Plant
Seed Production
Step 1
Prepare Your Space
0.5 cm
Seeding Depth
10 cm
Plant Spacing
30 cm
Row Spacing
4
Plants / Sq Ft
Vertical Growing
Yes: Trellis.
Method: Trellis.
Succession Planting
Yes.
Good Companions
Bad Companions
Step 2
Planting & Sprouting
Expect sprouts in 10–14 days
Growing Tips
- 1Grow flax in full sun, at least 6 hours a day.
- 2It likes light, well-drained soil, and a little compost raked in before sowing is plenty.
- 3Water when the top 2 to 3 cm of soil is dry, and do not let it sit soggy.
- 4Skip extra feeding, since rich soil makes floppy stems with fewer flowers.
- 5Knock aphids off with a spray of water, and pull weeds by hand while the seedlings are small, since they cannot compete.
Seedling Phase
Step 3
Growth & Maturity
~60
Days to Maturity
60 cm
Mature Height
30 cm
Mature Width
Pests to Watch For
Diseases to Watch For
Mature Plant
Step 4
Harvesting
Harvest Window
30 days
When to Pick
Harvest seed heads when dry
How to Harvest
- 1Enjoy the flowers in the morning, since each one opens early and drops its petals by afternoon.
- 2Once flowering slows, cut the plants back by a third to tidy them, or let them form round seed pods.
- 3Pull the plants once the pods are dry or after the first fall frost.
- 4Add the old plants to the compost pile.
Step 5
Saving Seeds
How to Save Seeds
Flax mostly pollinates itself, so seeds come true from plants that are not hybrids (hybrid F1 seeds will not). Wait until the round seed pods turn brown and dry and rattle when you shake them. Cut the stems into a paper bag and let them dry for a week in a cool, airy spot. Crush the pods gently and pick out the shiny flat seeds. Store them labelled in a cool, dark, dry place, where they keep for a few years.
Seed Production
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