Fall Pruning and Care Tips for Perennials and Shrubs

Cold temperatures in early November are a signal it’s time to prepare your shrubs and perennials for winter, a process that includes pruning, watering, and mulching.  

  

Flowering shrubs can be divided into two categories: spring blooming and summer blooming.  

  

At this time of year, spring blooming shrubs such as forsythia, lilac, ninebark, weigela and some varieties of hydrangea already have next spring's flower buds in place. They're said to bloom on "old wood" because soon after flowering this past season, they began to set the buds for next season's blooms. If you prune these shrubs now, you'll remove most if not all the flower buds. The time to prune ornamental shrubs that flower in spring and early summer, is within a month after they stop blooming.    

   

   

Summer flowering shrubs: Butterfly bush, blue mist spirea, and hardy hibiscus can be pruned now, because they bloom on next year's growth or "new wood".  These shrubs should be pruned now, down to 8” to 10”. 

If you’re growing re-blooming Endless Summer hydrangeas, they bloom on old and new wood. Pruning these cultivars includes deadheading spent flowers and pruning out any dead or diseased branches.  

  

If you’re not sure when to prune hydrangeas and other shrubs in your landscape, then don’t prune at all. Observe the plant through a season of growth and flowering and then decide if it blooms on old wood or new wood and prune accordingly. Even better, stop in and talk to us. We’ll help you with your pruning and planting questions.  

  

 

 

Perennials such as columbine, daylilies, phlox, peonies, salvia, veronica, and yarrow can be pruned to the basal foliage 3” to 5” above the soil line.

Around Thanksgiving, apply 3” to 4” of organic mulch. This will help minimize root damage due to temperature swings during the winter.  

 

  

  

Ornamental grasses can be pruned now, however they will add interest to your winter garden, so you can wait and prune them in early spring before they start to green up.   

 

  

You can prune roses back to between 24 inches and 30 inches. but delay severe pruning until spring. The exception would be dead, diseased, or damaged canes. More on roses in another blog.   

   

When it comes to trees, it’s better to wait until February or March to do any pruning. At this point in the season, trees focus their energy on their roots, as they prepare for winter. As a result, any pruning cuts made now won’t heal and will add stress to the tree. Better to wait until the tree is dormant to prune. The exception would be any dead, diseased or damaged branches and limbs. Those can and should be removed now.