Customer Service Hours
Mon-Fri 8-4 MST
Features
Family
Apiaceae
Native
Europe and Asia
Life Cycle
Perennial
Plant Height
Tall (Greater than 24")
Flower Color
Blue
Bloom Season
Summer to frost
Further Information
Plant Characteristics
- Attracts Pollinators
- Cut Flower
Growing Conditions
- Drought Tolerant
- Heat Tolerant
Plant Resistance
- Deer Resistant
- Rabbit Resistant
About Steel Blue Sea Holly Seeds
Eryngium planum
½"–1" flower heads made up of many tiny flowers start out green and turn to silvery-blue as the flowers open.
Planting More Flowers
Plant Spacing
A group of 3 seeds every 18"–24"
Hardiness Zones
5, 6, 7, 8, 9
Light Required
Full sun
Plant Height
Tall (Greater than 24")
Planting Depth
Press into surface
Planting Details
| Seed Depth | Press into surface |
|---|---|
| Seed Spacing | A group of 3 seeds every 18"–24" |
| Thinning | When 1" tall, thin to one every 18"–24" |
| Germination | 7–90 Days |
| Start Indoors | RECOMMENDED: 10 to 12 weeks before your average last frost date. Ideal soil temperature for germination is 70°–75°F. |
| Direct Sow | Sow in fall or late winter. |
| Special Sowing | For optimal germination, stratify sea holly seeds. Stratification is the process of subjecting seed to moist, cold treatment to break dormancy, which occurs naturally when seed is sown outdoors in fall. When starting seed indoors in spring, sow the seed into a container of moistened seed-starting mix, cover with clear plastic wrap, and leave the container in a refrigerator for 2 to 3 weeks, then move to a room temperature location to germinate. Keep soil evenly moist. |
| Growing & Harvesting | For longest vase life, harvest in the morning and change vase water frequently. For Drying: Harvest flowers when they are green; they will resist turning brown over time. |
Find Your Frost Date & Grow Zone
Average First Frost Date
October 19
Average Last Frost Date
May 19
Your Hardiness Zone is
5b
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