False Spirea Sorbaria sorbifolia

Sorbaria sorbifolia, or False Spirea, is a deciduous, erect, multi-stemmed shrub that is best grown in average, medium moisture, organically rich, well-drained soil. It flowers best when sited in full sun and spreads by suckers to form colonies. It is a hardy and aggressive plant and you should remove the root suckers promptly to control its spread and prune in late winter and early spring before new growth. To rejuvenate a tired plant, you can cut it close to the ground. Ural Spirea is a cultivar that does not have the invasive characteristic of the parent False Spirea, making it much improved variant for the home gardener. 

This coarse shrub grows to 5 to 8 feet tall (sometimes to 10 feet) and as wide. It displays masses of tiny white flowers in early summer and the deep green foliage resembles mountain ash to which it is related. It is sometimes planted en mass for erosion control.

Insects, Diseases, and Other Plant Problems

No serious insect or disease problems. It can spread aggressively by root suckers, particularly in loose soils  and seems to be less invasive in heavy clay soils.