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Cut flowers1 variety
Sea Holly
Eryngium planumDrought-tolerant perennial with steel-blue thistle-like flower heads for fresh and dried work.
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Days to maturity
365 daysDays to germ.
7–10 daysSpacing
18–24 inHeight
40–46 inSun
SunHow we grow it
Germination
- Days to germ.
- 7–10 d
- Depth
- 0 in
Culture
- Days to maturity
- 365 d
- Spacing
- 18–24 in
- Height
- 40–46 in
- Sun
- Sun
- Frost
- tender
- Hardiness zones
- 3–8
Harvest
- Handling
- Fresh or dried: Cut when the entire flower head and bracts turn blue or white, depending on the cultivar. Can be hung to air dry, or dry in desiccant to preserve more color.
Timing · Zone 5a
JanFebMarAprMayJunJulAugSepOctNovDec
Sow indoorsApr 9
Outdoor / directMay 21 – Jun 18
Bloom (from indoor)Apr 8
Bloom (from outdoor)May 20 – Jun 17
Windows are anchored to an average last frost of May 21 (1 year in 10 as early as Apr 29, as late as Jun 2) and an average first frost of Sep 18 (1 year in 10 as early as Sep 6, as late as Oct 8). In a late or early year, slide them with it.
Compare in the calendarTrials
Every Sea Holly sowingSeed sources, counts, ratings, and the observations kept against each one.Sea Holly trials