Blood-on-the-Snow
Hydrangea serrata
Hydrangeaceae · broadleaf deciduous shrub · introduced
Last updated
As of March 31, 2026, soil temperature at Kent / Auburn is 47.7°F. Blood-on-the-Snow, hardy to Zone Zones 6a–9b, is in early-season conditions in Zone 8b.
Mountain hydrangea (Hydrangea serrata, Hydrangeaceae) is a compact, rounded deciduous shrub from mountainous regions of Japan and Korea, reaching 2 to 4 feet tall and wide. Lacecap-type flower heads with showy peripheral florets and tiny fertile center florets change color from pink (alkaline) to blue (acidic) based on soil pH. Fall color is red to burgundy.
Mountain hydrangea grows in sun to part shade on moist, well-drained soil (pH 6.0 to 8.0) with medium growth rate, hardy in Zones 6a to 9b. It tolerates wind and attracts bees. The cultivar 'Blue Bird' is the primary selection. The plant is toxic to cats, dogs, and horses.