Eastern European native sea holly with branched stems of small steel-blue thimble flowers in summer, the stems and upper foliage equally steel-blue. The principal commercial cut-flower sea holly.
Hardiness ratings
| System | Rating | Temperature range | How to read it |
|---|---|---|---|
| USDA hardiness zone | Zone 4–9 | −34.4 °C to −1.1 °C | Plant tolerates down to this zone |
| RHS hardiness rating | H7 | down to −20 °C | Plant needs at least this level of cold tolerance |
| Canadian plant hardiness zone | Zone 4–8 | −29 °C to −1 °C | Plant tolerates down to this zone |
| Australian (ANBG) zone | Zone 1–6 | −15 °C to 15 °C | Plant tolerates down to this zone |
Growing notes
- Plant in sunny borders, gravel gardens, and prairie plantings — the principal commercial cut-flower sea holly, holds colour and structure when dried
- Excellent forage for bees and predatory wasps
- Distinct from the larger Eryngium maritimum (already in the database from batch 5) and the silvery Eryngium giganteum (batch 6) — E. planum is the steel-blue mid-border species
- Drought tolerant once established
Categories
Related plants
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