Common name(s): flat sea holly
Hardiness ratings: USDA zone 2~5 - 8~9
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Links for Eryngium planum
- All Things Plants - Community-assembled plant profile (5 varieties in database) (7 photos)
- BBC Gardening - Plant profile with horticultural details and garden uses. (1 photo). Also a page for 'Blaukappe'.
- Dave's Garden PlantFiles - Profile page with horticultural basics, and member-contributed photos and comments. (zone 5-8) (18 photos)
- Denver Botanic Gardens - Description, native range, and cultural requirements. (additional pages for other varieties) (zone 4) (8 photos)
- Digging Dog Nursery: Eryngium planum 'Blaukappe' - Catalog page with descriptive information (additional pages for other varieties) (zone 4)
- Hayefield: Eryngium planum 'Jade Frost' - Garden writer Nancy Ondra presents a plant growing in her garden, with description and photographs. (3 photos)
- Heritage Perennials: Eryngium planum Blue Cap - Profile with description and horticultural details. (additional pages for other varieties) (zone 2-9) (1 photo)
- Iris' Garden - Gardener in the Netherlands presents a photo of this plant, with basic horticultural information. (1 photo)
- Missouri Botanical Garden - Plantfinder page for one of the plants growing at the garden, with usually one or more photos, horticultural information, and noteworthy characteristics. (zone 5-9) (3 photos). Also pages for 'Blue Glitter', 'Blue Hobbit', 'Jade Frost', 'Tiny Jackpot', and 'White Glitter'.
- Ontario Rock Garden Society - Germination information (additional information for other varieties)
- Paghat's Garden: Eryngium x planum 'Sapphire Blue' - Illustrated articles by a gardener in the Pacific Northwest, with background and personal observations. (1 photo)
- Plant Delights Nursery: Eryngium planum 'Blue Glitter' - Catalog page with photo, horticultural basics, and descriptive blurb. (1 photo)
- Rainy Side Gardeners - Plant profile compiled by two gardeners in the Pacific Northwest. Includes propagation and pruning methods, and commentary. (zone 5-9) (2 photos)
- Rob's Plants - Plant profile with basic horticultural information and often personal observations. Also seed germination records. (zone 5-9) (3 photos)
- Wild Ginger Farm: Eryngium planum 'Blue Hobbit' - One of the plants featured on this specialty nursery's catalog page, with photo and brief description. (1 photo)