Spiraea thunbergii Thunberg spireaCulture: The Thunberg spirea is adaptable but performs best in full sun with well-drained soils. They are fibrous rooted and easy to transplant. This species seems to be in annual need of pruning to remove the finer stems that don't make it through the winter. Occasional pruning to remove the oldest branches to the ground should be undertaken after flowering to keep the plants looking their best. This species also responds nicely to rejuvenation pruning where all stems are cut close to the ground. Pruning is typically done following its early spring flowering. Occasional problems with aphids have been noted by Flint. Usage: This species is often used as a specimen or as part of a shrub border where its fine texture and early flower display serve as useful assets. The lack of uniformity does not make for good hedging material. A related hybrid of similar texture, size and flowers, but with superior habit is Spiraea x cinerea 'Grefsheim'. |