Fern-leaved Californian native cover crop with curling lavender-blue flower heads — among the highest-nectar plants per unit area of any cover crop.
Hardiness ratings
| System | Rating | Temperature range | How to read it |
|---|---|---|---|
| USDA hardiness zone | Zone 2–10 | −45.6 °C to 4.4 °C | Zones where it can be grown as an annual — not a frost-tolerance rating |
| RHS hardiness rating | H7 | down to −20 °C | Plant needs at least this level of cold tolerance |
| Canadian plant hardiness zone | Zone 2–9 | −40 °C and warmer | Zones where it can be grown as an annual — not a frost-tolerance rating |
| Australian (ANBG) zone | Zone 1–6 | −15 °C to 15 °C | Zones where it can be grown as an annual — not a frost-tolerance rating |
As a tender annual, Phacelia doesn't overwinter — the zone range shows where the growing season supports it. See the RHS rating for its actual cold tolerance.
Growing notes
- One of the strongest bee-forage cover crops available; flowering shoulds be timed to fill seasonal nectar gaps
- Not related to any major crop family — fits anywhere in a vegetable rotation without disease bridging
- Frost-tender — winter-killed in cold climates, leaving a useful in-place mulch
Categories
Related plants
Cross-check Phacelia against your zones