Cerinthe (Honeywort) in Zone 5a & 5b
Cerinthe major
Yes, cerinthe (honeywort) grows in zones 5a and 5b. Start seeds indoors Mar 29–Apr 5 and plant out May 10–May 17.
When to plant cerinthe (honeywort) in zone 5b
Zones 5a and 5b share the same average frost dates, so this page covers both.
Method: Either: Start indoors for an earlier harvest, or direct-sow outside for less fuss. Either works.
| Start indoors | Mar 29–Apr 5 |
|---|---|
| Direct sow / transplant outside | May 10–May 17 |
| Estimated bloom | Jul 24–Jul 31 (~75 days after planting) |
Spacing: 2 per square foot (square-foot-gardening spacing). Mature height: 1-2 ft.
Plant alongside it in zone 5b
These go outside within two weeks of cerinthe (honeywort) in zone 5b, so one planting day can cover them.
- NasturtiumMay 17–May 24
- MarigoldMay 17–May 24
- African DaisyMay 10–May 17
- Amaranthus (Love-Lies-Bleeding)May 10–May 17
- Ammi (False Queen Anne's Lace)May 10–May 17
- Ammobium (Winged Everlasting)May 10–May 17

Cerinthe, commonly called honeywort, doesn't look like a typical cut flower. Its waxy, blue-purple bracts have an almost succulent texture, more sculptural than floral, which is exactly why it's grown.
How cerinthe (honeywort) fits zone 5's season
Zone 5b's frost-free window runs about 148 days, from May 10 to October 5. Cerinthe (honeywort) needs about 75 days from sowing to first bloom.
Cerinthe (Honeywort) planting windows in every zone
Zone 5b is highlighted. Useful for comparing against a neighbouring zone, or for a garden somewhere else.
| Zone | Start indoors | Sow or plant out | Bloom |
|---|---|---|---|
| 2a & 2b | Apr 8–Apr 15 | May 20–May 27 | Aug 3–Aug 10 |
| 3a & 3b | Apr 18–Apr 25 | May 30–Jun 6 | Aug 13–Aug 20 |
| 4a & 4b | Apr 3–Apr 10 | May 15–May 22 | Jul 29–Aug 5 |
| 5a & 5b (your zone) | Mar 29–Apr 5 | May 10–May 17 | Jul 24–Jul 31 |
| 6a & 6b | Mar 14–Mar 21 | Apr 25–May 2 | Jul 9–Jul 16 |
| 7a & 7b | Feb 27–Mar 6 | Apr 10–Apr 17 | Jun 24–Jul 1 |
| 8a & 8b | Feb 11–Feb 18 | Mar 25–Apr 1 | Jun 8–Jun 15 |
| 9a & 9b | Jan 4–Jan 11 | Feb 15–Feb 22 | May 1–May 8 |
| 10a & 10b | Dec 19–Dec 26 | Jan 30–Feb 6 | Apr 15–Apr 22 |
| 11a & 11b | Nov 20–Nov 27 | Jan 1–Jan 8 | Mar 17–Mar 24 |
Bloom dates are about 75 days after the sow or plant-out date, not after starting seeds indoors.
Zone 2 sows before zone 3 here, which looks wrong and is not. USDA zones rank winter cold, not season length, and zone 2 is mostly interior Alaska, where hard winters come with warm summers. More on what a zone measures.
Good companions
No well-established companions for cerinthe (honeywort).
Where to buy cerinthe seeds
None of the seed suppliers we list carries cerinthe seeds right now. A local garden center or a specialty seed house is the place to look.
See why we recommend these suppliers →
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See it growing
Search YouTube for "growing cerinthe (honeywort)" videos → (a live search, not a hand-picked video; results vary and aren't vetted by us)
← Back to the full zone 5b calendar · Plan your beds in the Garden Designer →

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Growing Cerinthe (Honeywort) in USDA zone 5b: when to start seeds indoors, when to direct-sow, and when to expect a bloom.
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