FoliageSea Holly
Eryngium planum
Sea Holly (Eryngium planum) is a perennial, hardy in USDA zones 5-9, that matures to about 2-3 ft × 1-2 ft. It does best in full sun with low water needs in well-drained, occasionally-dry and very-dry soil. Expect blue, silver and purple blooms in summer and fall. It attracts bees, butterflies and pollinators, stands up well to deer, drought and dry soil, grows happily in containers.
- USDA zones
- 5-9
- Sun
- Full sun
- Water
- Low
- Mature size
- 2-3 ft × 1-2 ft
- Maintenance
- Low
- Soil
- Well-drained, Occasionally-dry, Very-dry
- Bloom color
- Blue, Silver, Purple
- Bloom season
- Summer, Fall
- Attracts
- Bees, Butterflies, Pollinators
- Tough against
- Deer, Drought, Dry soil, Poor soil, Rabbits, Salt
- Native to
- Central and southeastern Europe
In the landscape
Data sources
Freeze survival
Will it survive your winters?
Hardiness zones show a normal bad winter. We check the worst one — Sea Holly is hardy to about -20°F (estimated from USDA zone 5), so we'll score it against the real coldest nights your area has actually had.
Powered by ~35 years of daily lows from the nearest NOAA weather station. A risk read, not a guarantee — a sheltered spot or mature plant beats the odds.
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