Spiraea tomentosa (Steeplebush)

An increasingly uncommon species in the wild due to wetland loss and drainage, steeplebush's astringent, densely-haired foliage confers confirmed deer resistance while serving as a documented larval host for the Spring and Summer Azure butterflies alongside three specifically named moth species - real ecological weight for a shrub that's earned the nickname "hardhack" for its stubborn resilience.

Species Overview

Spiraea tomentosa, commonly called steeplebush or hardhack, is a suckering deciduous shrub native to wet meadows, boggy fields, marshes, and lake margins across the eastern United States and Canada, growing 2 to 4 feet tall. Distinctive spire-like clusters of pink to rose-purple flowers bloom from top to bottom July through September, above woolly-textured leaves that turn reddish-gold in fall.

Application

• High-quality wetland restoration - an uncommon species worth reintroducing where lost
• Larval host habitat for the Spring and Summer Azure butterflies and three named moths
• Deer-pressured wet meadow and pond-margin plantings
• Rain garden, shoreline, and naturalized swale plantings

Growing Conditions / Specification Data

• Light: Full Sun to Part Shade
• Soil/Moisture Tolerance: Moist to wet, acidic soils; tolerates a wide range of soil conditions
• Plant Type: Shrub
• Mature Height: 2-4 ft.
• Fall Color: Red
• Bloom Color / Period: Pink; July-September
• Wetland Indicator Status: NI (No Indicator) - see flags
• Native Range: Northeast/Mid-Atlantic (full list)
• Hydrology: Mesic-Moist
• Root Depth: Moderate (12-24 in.)
• Salinity Tolerance: Low
• Growth Rate: Moderate
• Drought Tolerance: Moderate
• Flood Tolerance: Moderate - Often found in wet meadows and bog margins in addition to drier sites; tolerates periodically wet soil.
• Shade Tolerance: Intermediate
• Growth Habit: Multi-stemmed/Thicket-forming - suckering
• USDA Hardiness Zones: 3-7
• Deer Resistance: Yes (Rarely Damaged)
• Pollinator Value: Larval host, supports butterflies, supports moths

Planting Guidance

• IMPORTANT: uncommon in the wild and found in high-quality wetland habitats, with populations declining due to urban sprawl, drainage projects, and wetland destruction - worth conservation awareness and reintroduction where appropriate. Flowers on new wood, so prune in late winter or very early spring if needed.