If you have ornamental shrubs in your yard, you’ve probably done some light trimming here and there to remove dead or diseased branches, or to tidy up the overall shape. But for some plants, doing some thorough rejuvenation pruning can dramatically improve their appearance and health over time. It’s especially useful if you have very old, established shrubs—rejuvenation pruning will help restore them to their former glory! Here’s how to do it properly without hurting your plants.
What is Rejuvenation Pruning?
Rejuvenation pruning is a more drastic cutback of your plants, removing old growth to make room for new, thicker, healthier growth. Instead of just pruning the damaged parts or making the shape more uniform, you cut the branches drastically. Not all plants tolerate rejuvenation pruning well, some do best if the pruning is completed gradually over the course of three years, and others can be completely cut back at once.
Rejuvenation Pruning as Preventive Plant Care
This form of pruning is like a preventive treatment for your plants. Those old, tired branches are much more susceptible to disease and pest infestations. Getting rid of the weak stuff so a fresh set can take its place will turn back the clock for your plant, helping it stay healthy for longer. After you thin them out, a lot more sunlight will be able to reach the branches in the middle, and new growth will soon follow!
How to Rejuvenate Old Shrubs
Rejuvenation pruning should be done in spring or early summer—that way, all that new growth will appear right away during your plant’s summer growth spurt. Spring-blooming shrubs like lilacs should be hard pruned immediately after blooming, because if you prune them in spring you’ll remove all the flower buds. summer-blooming shrubs can be hard pruned in spring. We recommend using long-handled pruners so you can make clean, precise cuts, but thicker branches may require a pruning saw.
Remember to practice good pruner hygiene! Disinfect the blades of your pruners thoroughly before trimming a new plant to reduce the spread of bacteria.
Before you start cutting back your shrubs, determine if they prefer gradual cutbacks or if it should be completed all at once—that’s referred to as “hard pruning.”
Shrubs that prefer gradual pruning include:
- Burning Bush
- Purple Sand Cherry
If you’re going to make your cuts gradually, remove ⅓ of the branches in your first year, cutting them all the way down to the ground. The following spring, remove half of the remaining old branches. In your final year, remove the last remaining old branches.
Shrubs that prefer hard pruning include:
When hard pruning, make your cuts ¼ inch above a branch node at a 45° angle, with the highest part of the cut sitting right above the node. Nodes are the bumpy ridges along stems where new branches emerge. This will encourage outward growth, preventing future branches from rubbing together and creating wounds on your plant.
Plants That Don’t Respond Well to Rejuvenation
This method doesn’t work for every kind of shrub—you’ll want to avoid using it on tree-like shrubs that have one large main trunk. It also doesn’t work for shrubs that have been grafted to a root stock. If you cut those back, the new branches that appear will come from the root stock plant, and you’ll lose out on the ornamental features of the shrub.
If you have any questions about rejuvenation and preventive pruning in Edmonton, or if you need to stock up on the necessary equipment, visit Salisbury Greenhouse in Sherwood Park and St. Albert to explore our collection of high-quality tools to get the job done right. You’re welcome to ask us any questions about proper techniques. We’re happy to help! And if you aren’t confident you can complete the job on your own, don’t hesitate to contact our landscaping team or ask to speak with our foreman Brian, our resident pruning expert!