
Big Blue sea holly’s spiky features — sharply pointed leaves, bracts and inflorescences — give it an otherworldly feel, but this fascinating perennial even works in traditional garden settings. It has a dip-dyed appearance, as the upper flowers, stems and leaves are deep blue-violet, fading into silvery blue-green, grounded with deep blue-green basal foliage.
The thistle-like, violet-blue flowers bloom from June through August. In the fall and winter, flowers hold their form as a dried seed head. Flowers also attract a variety of bees, butterflies and other pollinators. The plants grow up to 2½ feet tall and feature strong stems.
Both blooming and dried flower heads are ideal as cut flowers. Big Blue sea holly is a drought tolerant plant that prefers well-drained, poor soils. It’s hardy in USDA Zones 5-9.


Explore the July 2024 Issue
Check out more from this issue and find your next story to read.
Latest from Greenhouse Management
- Flexible fungicides
- Super Charged Moon Juice from Moon Valley Nurseries now available nationally
- 2025 Proven Winners Horticulture Scholarship applications now open
- How to improve inventory and shipping management in the greenhouse
- Leading Women of Horticulture: Anna Ball, Ball Hort, and Terri McEnaney, Bailey Nurseries
- GM CEA HERB Part 2: A guide to increasing the sowing density of culinary herbs
- GM CEA HERB Part 1: Best practices for producing culinary herbs in controlled environments
- USDA fires experts on invasive pests, including Asian citrus psyllid, chilli thrips