The Golden Rule When Pruning Spring-Blooming Shrubs

Spring-blooming shrubs flower on the previous year’s wood. Prune just after the display fades to assure they’ll form buds next year. This applies to common varieties like lilac, forsythia, weigela, mock orange, some hydrangeas and spireas and any woody plant that flowers in spring. Clemson College of Agriculture’s cooperative extension service offers helpful suggested pruning times for common flowering trees, shrubs, and vines, including summer-flowering plants and spring-flowering plants.

Reasons for Pruning

Size Control

An obvious reason to prune is to keep shrubs from taking over. Branches can damage home siding, intrude onto porches and decks, and obstruct paths.

Cosmetic Shaping

Some shrubs seem most attractive when trimmed into a rounded form, others when shaped like a fountain. If a natural shape is preferred and space is available, pruning may not be necessary. However, most varieties look their best and stay healthiest with occasional trimming.

Keeping Plants Healthy

Pruning dead or diseased branches and sections can rejuvenate sluggish shrubs. Keeping plants compact increases blooms too. It is surprising how quickly they will bounce back after an extensive trimming. Aging, woody lilacs with only a few blooms near the top can be severely pruned, nearly to the ground, often experiencing a sort of second life.

Choose the Correct Technique for Your Intent

Renewal Pruning

Renewal pruning means cutting back, nearly to the ground. As mentioned above, in reference to lilacs, renewal pruning can give new life to leggy shrubs, by triggering bushy growth.

Heading Back

Heading back basically means cutting branches longer than the rest, or sometimes all of the outer branches, to create a more regular shape. Cut each branch on a slight slant, just above a bud. Choose a bud that is facing the direction you wish the branch to grow – usually outward from the trunk. To keep a shrub from becoming sparse in branches near the base, the heading back process must be done at all levels from the base of the trunk to the top of the foliage.

Thinning

This refers to cutting some branches back to the trunk or a main branch throughout the plant to create a balanced shape. Thinning helps keep the interior of a shrub healthy and filled with foliage. This process assists in limiting a shrub’s size without resulting in legginess. With proper watering, feeding, and a bit of pruning after flowering each season, most spring shrubs can beautify lawns for years to come. Not sure you’re up to the pruning task yourself? Contact our arborists today for details about our shrub and tree care programs.