About Spiraea tomentosa L.
Spiraea tomentosa L. grows up to four feet high, and prefers moist to wet soil and full sun. It blooms in summer. Each tiny pink flower is about 1/16 of an inch wide, and arranged in narrow, pyramid-shaped flowerheads that can grow up to eight inches long. After flowering, the plant produces small, dry, brown fruit. Its specific epithet tomentosa refers to the dense white-woolly tomentum that covers the undersides of its leaves and its stems. It shares similar characteristics with Spiraea douglasii. The plant bug Plagiognathus fuscosus breeds on this species, which is also commonly called steeplebush. A number of different bee species visit its flowers: the non-native Apis mellifera, Bombus griseocollis, Bombus impatiens, Lasioglossum atwoodi, Lasioglossum hitchensi, and Hylaeus mesillae. Steeplebush is known to have astringent properties, and has been used for medicinal purposes. This plant is listed as hardy in USDA hardiness zones 4 to 8.
