Pruning Flowering Shrubs

Pruning the flowering shrubs in your landscape isn’t difficult if you understand these practical rules. Practical rule number one: prune spring flowering shrubs after they bloom and before they set seed. 

Spring blooming shrubs such as forsythia, lilac, ninebark and weigela already have this spring's flower buds in place. They're said to bloom on old wood because soon after flowering last season, they began to set the buds for this season's blooms. If you prune these shrubs now, you'll remove most of the flower buds. The time to prune ornamental shrubs that flower in spring and early summer, is within a month after they stop blooming. 

Practical rule number two: prune summer flowering shrubs such as butterfly bush, blue-mist spirea  and hardy hibiscus in late winter or early spring, because they bloom on this year’s growth or “new wood”. Practical rule number three: don’t prune. If you’re uncertain about the blooming habits of the shrubs in your landscape, don’t prune until you’ve had time to observe each plant’s growth and bloom cycle. Then you can employ practical rule one or practical rule two, whichever is applicable. Practical rule number four: prune anytime there is a need to remove dead, damaged or diseased branches. It’s always the right time to remove any branches that pose a hazard. The shrub will recover over time. 

Summer flowering hardy hibiscus and butterfly bushes do best if you cut them hard to the ground now. You can use a lopper to cut the larger canes.  

Prune Caryopteris back to about six inches, if you want to maintain the same height each year.

 If you want your Blue Mist spirea to increase in size each season, prune it back by one third now.  After you're done pruning, give your ornamental shrubs a good drink. Wait another month to feed your shrubs. When you do, select a fertilizer with a higher Phosphate formula, such as 11-15-11. If you have questions about pruning in general or how to prune a particular shrub, stop by our Diagnostic Center. We'll help you figure out what to do to keep your shrubs healthy and blooming for many seasons.