Common name: Sea holly
Scientific name: Eryngium spp.
Plant type: Perennial
Height: 15-24 inches
Width: 8-12 inches
Where to plant: Full sun
Water requirement: Drought tolerant (once established)
Preparing the soil: Average to poor soils
Hardy: Zone 3
While this plant's spiny leaves might vaguely resemble the thistle you spend hours trying to get rid of, this is a cultivated garden plant that offers bright steel-blue, conelike flowers with silvery leaves. Basal blue-green leaves make it a beautiful accent plant that is drought tolerant and can withstand hot, sunny exposures with little water once it is established. The spiny leaves make it deer resistant. Long-lasting blue cone flowers also work well in dried floral arrangements.
Julie McIntyre, Summerland Gardens