It’s an age-old question- one that we see a lot of in the Extension Office: when do I prune my plants? Gardeners young and old struggle with pruning, and for good reason. You don’t want to kill your prized roses, and you don’t want to reduce the number of azalea flowers you see in spring, so what is the ideal pruning time?
The only way you can find the perfect pruning time is by knowing the species of the plant and then researching when to prune.
That being said, I have run into the situation where a homeowner has no clue what the plant is, but they need to trim it back before it takes over the front yard. There is no foolproof way of determining what the ideal pruning time is without knowing the species beforehand, but there are some guidelines that you can use.
Does the plant you have in mind flower in spring? Spring flowering ornamentals such as flowering dogwood, azaleas, and Bradford pears bloom on old wood from the previous year. If you prune before these plants flower, you will remove the old stems that produce buds. So, enjoy the impressive displays these types of plants produce first, then trim them.
Perhaps the plant in question flowers in summer. These shrubs and trees bloom on new growth that is produced that year. This means you want to prune them in late winter before spring growth begins. This way there is an abundance of new growth to produce flower buds.
Maybe the plant you are wanting to prune is an ornamental plant that is not grown for its showy flowers. These plants are the most forgiving in terms of pruning times: they can be pruned in late winter, spring, or early summer.
Do not prune any of your plants in fall and early winter. Pruning stimulates growth in most plants, and if you prune before winter dormancy the plant will use energy to put out new growth. This new growth is then killed by the cold temperatures, and the plant will be weakened going into winter.
Often you will come across a shrub that has been sheared into a shape without any consideration for the natural form of the plant.
Over time this results in a very dense shell of leaves on the outside of the plant which can reduce air and light into the middle of the plant.
This situation often results in the spread of fungus or disease, and so to restore the natural structure of the plant it needs to undergo renewal pruning. Renewal pruning entails cutting the entire plant down to within 6-12 inches of the ground. This has to be done at the very end of winter as the plant is getting ready to put out new shoots. This ensures the shrub will have the energy to put forward a large flush of growth and there will be plenty of time for the plant to recover.
Make sure that you use appropriate protective gear and always disinfect your tools between cuts. This can be accomplished by using a 10 percent bleach solution, and it will prevent the spread of any fungus or disease as you move from plant to plant.
If you are curious about the techniques of pruning Forsyth County Extension is hosting a pruning webinar at 6 p.m., Feb. 19. We will be showing a pruning presentation from UGA Horticulturalist and Landscape Specialist Dr. Bodie Pennisi. Dr. Pennisi discusses the concepts behind pruning as well as different methods of pruning.
The webinar is open to the public and is free of charge; however, we do ask that you register for this event.
Contact the extension through email at firstname.lastname@example.org or call 770-887-2418 to register.
Shannon Kennedy is the Agriculture and Natural Resources Educator for the Forsyth County Extension.