"Limemound" spirea (Spiraea japonica or Spiraea x bumaldi "Limemound") adds vivid color to your garden even when it's not in bloom. The deciduous shrub, suitable for U.S. Department of Agriculture plant hardiness zones 3 to 9, has bright yellow-green foliage with pink, flat-topped flowers from May through July. "Limemound" reaches 2 to 3 feet tall and 3 to 4 feet wide, but can be kept more compact with annual pruning.
1 Spray the blades of your bypass pruners with household antiseptic cleaner and wipe them dry with paper towels. This cuts the potential of spreading disease from plants previously pruned.
2 Thin dead, old or weak stems all the way to the ground with bypass pruners whenever you notice them.
3 Remove the rest of the growth back to 4 to 6 inches from the ground, cutting at a 45-degree angle, 1/4 inch above a bud on each stem. "Limemound" blooms on new growth.
4 Deadhead the flowers after blooming, cutting at the next leaf or bud below the flower, or to the next stem down if you want to shape the plant. This prompts another round of bloom.