Evergreen thistle-like leaves and steel blue flowers makes the flat seaholly or blue eryngo a favorite perennial for sunny, gravelly gardens. Eryngium planum is a hardy herbaceous perennial native to dry rocky mountain slopes of southeastern Europe to central Asia. It has a dense basal rosette of heart-shaped, coarse, spiny dark green leaves that are leathery. In summer it produces plume-like flowers with a barreled cluster of fertile, tiny pale blue flowers surrounded by many spiny bracts (modified leaves) of blue-gray. The long-lasting flowers are borne atop branched stems that have blue-green lobed leaves. Flowers are highly attractive to bees and butterflies. If the seedheads are allowed to mature, it may self-sow.
It is a lovely and interesting perennial for sunny borders, and its cool, architectural flowers compliment many other brightly colored ornamentals. The flowers make long-lasting cutflowers for fresh and dried arrangements. (Info source: Learn2Grow.com)
Genus - Eryngium
Species - Planum
Common name - Blue Eryngo
Pre-Treatment - Required
Hardiness zones - 5 - 9
Height - 30"-36" / 76.2cm - 91.4cm
Spread - 15"-20" / 38.1cm - 50.8cm
Plant type - Perennial
Vegetation type - Deciduous
Exposure - Full Sun, Partial Sun
Growth rate - Medium
Soil PH - Neutral, Alkaline
Soil type - Clay, Loam, Sand, Well Drained
Water requirements - Drought Tolerant, Average Water
Landscape uses - Cutflower, Dried Flower/Everlasting, Mixed Border, Rock Garden / Wall, Wildflower
Germination rate - 72%
Bloom season - Summer, Late Summer, Early Fall
Leaf / Flower color - Green, Dark Green, Gray / Light Blue, Gray Green, Silver
Useful Info | |
Germination | 1. Soak in warm water for 24 hours. 2. Place the seeds in a moist sterile soil or vermiculite and zip in airtight bag. Keep in the fridge for 30 days at 33 to 41 degrees Fahrenheit (+2 – +4C), don't let to dry out. 3. After the stratification, plant 1/16” deep in a moist, well-drained soil or germination medium. Tamp the soil. Cover with clear plastic or grass, keep moist in warm and bright place. Remove the cover just after the seeds starts to germinate. |