Scarlet Flax in Zone 8a & 8b
Linum grandiflorum
Yes, scarlet flax grows in zones 8a and 8b. Plant it outside Mar 25–Apr 1.
When to plant scarlet flax in zone 8b
Zones 8a and 8b share the same average frost dates, so this page covers both.
Method: Direct sow: Direct-sow outside. It doesn't transplant well, or doesn't need the extra time indoors.
| Start indoors | Not typically started indoors |
|---|---|
| Direct sow / transplant outside | Mar 25–Apr 1 |
| Estimated bloom | Jun 3–Jun 10 (~70 days after direct-sowing) |
Spacing: 4 per square foot (square-foot-gardening spacing). Mature height: 1-1.5 ft.
Plant alongside it in zone 8b
These go outside within two weeks of scarlet flax in zone 8b, so one planting day can cover them.
- NasturtiumApr 1–Apr 8
- MarigoldApr 1–Apr 8
- African DaisyMar 25–Apr 1
- Amaranthus (Love-Lies-Bleeding)Mar 25–Apr 1
- Ammi (False Queen Anne's Lace)Mar 25–Apr 1
- Ammobium (Winged Everlasting)Mar 25–Apr 1

Scarlet flax is a wispy annual whose individual flowers last a single day. The plant compensates by producing a great many of them.
How scarlet flax fits zone 8's season
Zone 8b's frost-free window runs about 230 days, from March 25 to November 10. Scarlet flax needs about 70 days from sowing to first bloom.
Scarlet Flax planting windows in every zone
Zone 8b is highlighted. Useful for comparing against a neighbouring zone, or for a garden somewhere else.
| Zone | Start indoors | Sow or plant out | Bloom |
|---|---|---|---|
| 4a & 4b | Not usually | May 15–May 22 | Jul 24–Jul 31 |
| 5a & 5b | Not usually | May 10–May 17 | Jul 19–Jul 26 |
| 6a & 6b | Not usually | Apr 25–May 2 | Jul 4–Jul 11 |
| 7a & 7b | Not usually | Apr 10–Apr 17 | Jun 19–Jun 26 |
| 8a & 8b (your zone) | Not usually | Mar 25–Apr 1 | Jun 3–Jun 10 |
| 9a & 9b | Not usually | Feb 15–Feb 22 | Apr 26–May 3 |
Bloom dates are about 70 days after the sow or plant-out date.
Good companions
No well-established companions for scarlet flax.
Where to buy scarlet flax seeds
Botanical Interests · True Leaf Market (scarlet flax seeds)
See why we recommend these suppliers →
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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)
← Back to the full zone 8b calendar · Plan your beds in the Garden Designer →

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Growing Scarlet Flax in USDA zone 8b: when to start seeds indoors, when to direct-sow, and when to expect a bloom.
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