- Name: Blue Mink Ageratum - Other Common Names: Flossflower / Garden Ageratum - Scientific Name: Ageratum Houstonianum Blue Mink - Color: Powder Blue - Plant Seeds: Outdoors After Frost / Indoors Weeks Before Last Frost - Bloom Time: Summer - Early Fall - Hardiness Zone: Annual - Plant Height: 10 - 18" - Plant Spacing: 6 - 9" - Light Requirements: Sun - Soil & Water Preferences: Average - Quantity: 100 Seeds - Other: Blue Mink Is A Dwarf Ageratum With Fuzzy Double Flowers That Will Lure In Bees & Butterflies. This Native Of The West Indies & Central America Makes A Great Border Plant, Ground Cover, Or Can Be Grown In Containers.