Save the Blooms - Don't Prune Too Soon

Posted by Andrea Cummins, Douglas County Extension

Ah, spring is here…at least it feels like it today. And the forecast is looking good for the next week or so, maybe we are finally over the hump? Well time will tell, but you have to enjoy it while we can during the unpredictability of March. I know this kind of weather makes me look out my office window and plan a weekend of cleaning up my yard. It’s time to check for bulbs poking out of the mulch, cut back ornamental grasses and Russian sage, and prune shrubs to clean it all up a bit right? “Yes” to the first two, but only “maybe” to the last.

Pruning this time of year can lead to unfortunate results. You need to know what type of shrub or tree you have prior to taking out those pruners and cleaning up. If you aren’t careful, you might cut off all those flowers you wanted the shrub for in the first place.

Oops! 

Spring flowering shrubs (think lilac and forsythia) set flower buds in late summer or early fall, on old wood. Pruning too late in the year will result in reduced flowering for the next spring -- the time to prune these plants is in early summer right after they are done flowering. Summer blooming shrubs (Rose of Sharon and some hydrangea) can be pruned in March and early spring prior to new growth. These types of shrubs set flower buds on the new wood each year, so it is safe to prune them in the early spring.

Don't cut here!

Think before you prune in order to make sure you will have the blooms you have been waiting for in the next few weeks. For more information check out, http://cmg.colostate.edu/gardennotes/619.pdf.