Many varieties fall into this category. It includes Potentilla, Shrub Roses, Rose of Sharon, Hypericum, Summer Flowering Spirea and more. Trimming in early spring will increase your bloom for summer. Unlike the spring flowering plants these shrubs bloom on new growth of the year. Trimming
summer flowering shrubs is not always needed but is a great tool to keep them the size you want for your situation. Sometimes a hard pruning is used to eliminate old woody growth that is not very attractive and encouraging new growth that will bloom well. We’ll talk about a few common varieties found in landscapes.
Shrub Roses are commonly used for their great color all summer long. Shrub roses are the most common type used in landscapes. Trimming shrub roses annually is not always needed but occasional hard pruning to twelve inches tall or so, will help keep them in good shape. Trimming back about one third every year in early spring will promote many new shoots and lots of blooms. Trimming after they bloom is not necessary to keep them blooming however a light trimming in summer after a round of blooms will usually encourage more blooms and eliminate spent flowers and rose hips, or seeds.
Potentilla and Summer Flowering Spirea varieties should be trimmed back about one third. This will encourage new growth with lots of blooms. This is usually done before or just as new growth appears. If it is three feet tall cut it back to two feet. This will help it stay in the area it was designed to fill. Every three to five years you can cut this group of shrubs to six inches tall to rejuvenate them. By removing the woody stems that may not bloom or even have much foliage you will encourage new growth that will bloom profusely all summer long. As with the roses a light trimming in midsummer after a bloom period will encourage more new growth. This new growth should produce lots of late summer flowers.
Rose of Sharon is a large growing summer flowering shrub. It can be trimmed up like a tree or maintained as a very large shrub. Trim this plant back about one fourth each year. If it is six feet tall cut it back to four to four and half. When you trim you will get many new shoots coming out that
should all flower nicely. Trimming back at varying heights each year will eliminate the stubby look that sometimes comes with continued trimming at the same height.
If in question on how to trim a particular shrub it is always wise to ask for some advice. The professionals at Landscape Consultants will be glad to advise you.