When do I prune?

Working in the Landscape Horticulture profession for over 30 years I have heard one question asked more often than any other- When do I prune?

One thing to note before we dive into pruning: If you are just beginning to plan your garden-, make sure the plant you are choosing will fit the space you have planned for it over time.

Many plants will benefit from pruning them at the appropriate time to help keep them healthy, structurally sound, increase flower and bud formation as well as fruit production.

When it comes to most plants common in our landscapes the general rule of thumb is to prune early blossoming trees and shrubs immediately after they bloom and well before they have a chance to set flower buds for the following season.  Good shrub examples of this are the Mop Head and Lace-Cap Hydrangeas, Lilacs, Azaleas, Rhododendron and certain species of Spireas such as Bridal Veil Spirea.  I mentioned to prune immediately after flowering as in many cases the flower buds are set by mid-summer.


During the “Polar Vortex” winters of 2013-14 and 2014-15, many of our local Hydrangeas had most of their flower buds “naturally” pruned of due to the extremely low temperatures.   Many frustrated gardeners wondered why their Hydrangeas did not bloom those following summers. In fact many Hydrangea stems died clear to ground level.

New variety of Hydrangeas have both buds that form on previous year’s wood and also flower buds that form on current year’s wood which just about guarantees yearly blossoming.  “Endless Summer” Hydrangea is one of these newer cultivars of Hydrangea.

Trees and shrubs that flower on current seasons wood includes familiar ones like Rose-of-Sharon, some Viburnums, Spireas such as Gold Mound and Little Princess, Smokebush and Panicled Hydrangeas (white, cone-shaped flowers) and Golden Rain Tree.  You can prune these shrubs and trees at any time before they leaf out.  If they have leafed out, pruning the new growth could sacrifice blossoms later in the summer.  Generally, late winter is a good time, as the plants will heal quickly from the pruning cuts.

If you have doubts when to prune be sure to do the research so you will not be disappointed later in the growing season.

Eichenlaub can help you with your landscape design, installation and maintenance needs; just give us a call or send an email to set up an appointment to meet with one of our consultants.

Contact me if you have any further questions.

– Kevin Anthony Prall


(412) 767-4769