Renewal pruning is the absolute best way to rejuvenate older, overgrown shrubs, and also the best tool for maintaining healthy shrubs! This version of a plant ‘buzz cut’ is a much-needed refresher and a very important chore for maintaining and revitalizing a tired, old, overgrown plant!
Maybe your Lilac is simply old and overgrown and you really need to rejuvenate it. Maybe you just moved into a new home and have a hedge of overgrown, forgotten Forsythias, or a single Rose bush that has become sparse and leggy. Even a consistently sheared foundation row of Evergreens can start to look less stellar as each year passes. It’s time to break out those pruners!
Here’s how to properly give your plant a reboot and not end up with the plant version of the bowl cut!
The Importance of Renewal Pruning
The key to a successful renewal is to cut out the oldest stems about every third year. Simply cutting out the oldest, fattest stems of an overgrown shrub, allows for younger, thinner stems to remain in place to flower and fruit. This will keep the growth in balance and maintain the best flowering and fruiting all while keeping the natural shape and size of the shrub!
By removing older, diseased, neglected, damaged, and/or less productive stems, you make room for younger and more vigorous ones. You open up the plants with better air circulation and stimulate better flowering and fruiting. Cleaning out the interior of a plant eliminates the ‘rats nest’ of any build-up of dead leaves, trash, broken twigs, and branches, and removes hiding spots for disease, fungus, and insects.
Types of Renewal Pruning
- Renewal Pruning - Is used to refresh and maintain overgrown shrubs without disturbing the flowers and fruiting. It is typically done every 3-4 years by cutting out up to about ⅓ of the oldest, fattest stems right down to a bud closest to the soil line - leaving the younger and thinner stems in place. If done yearly you may only need to remove a stem or two depending upon the genus. This can be done in late winter or early spring, or you can allow the plant to bloom and then cut out those fattest stems right after the spring bloom finishes.
- Complete Rejuvenation Pruning - Good for rejuvenating older, neglected, and overgrown shrubs that need a complete renewal to avoid replacement. Simply cut all stems down to a bud closest to the soil line of all stems. New shoots will develop from the roots, starting the plant over. Typically done in winter or early spring for best results. Sounds drastic, but well worth it while the shrub regrows all new stems from the established root system.
What and When to Renewal Prune
Regular renewal pruning keeps the plants looking their best. Even the more severe rejuvenation can save you thousands of dollars from having the older shrubs taken out and replaced! By thinning out old shrubs, you can bring them back to life with just a few easy steps.
But the timing of your pruning is the key to success!
Old Wood Blooming Shrubs
Many early spring flowering plants have already formed their flowers on the growth from last year (on old wood), so pruning at the wrong time will eliminate those flowers for this spring. So if you want to enjoy the blooms first and then cut out the oldest stems you may.
If an unavoidable spring renewal pruning is necessary, and it is a spring-flowering shrub, please know that your shrub will not flower the year that you prune it. It’s just not possible for it to regrow that quickly and produce flowers. But by the following year, the flowers should be abundant.
New Wood Blooming Shrubs
Other shrubs that bloom on new wood like many of the smaller Spiraeas, Butterfly Bush, Diervilla, Caryoptereis, Shrub and Hybrid Roses, or Crape Myrtles can simply be cut down in late winter or early spring and new flowers will develop on the new growth each year.
Dormant plants are also easier to prune because you can see the branching without the leaves in the way. Larger, older selections can be hard pruned by removing the oldest stems out to the ground in the winter, leaving the slender, smaller stems to take over. Because you are removing the entire branch to the ground, there is no worry about missing out on that year's flowers or fruit.
Reblooming Shrubs
For reblooming varieties like some Bloomerang Lilacs, Encore Azaleas and Reblooming Weigela, it is recommended Renewal prune right after the first flush of flowers for best results.
Broadleaf Evergreens
Renewal pruning techniques help promote bushier growth closer to the ground of older Broadleaf Evergreens such as Boxwood, Holly, Euonymus, and evergreen Viburnums. This also helps remove winter dieback and injury while encouraging new growth from within to produce a fuller plant. These plants do benefit from a yearly cleaning out of their interiors where dead needles and branches collect, crowding and shading out the interior - leading to insect, disease and moisture issues from the lack of sunlight and air circulation.
Coniferous Evergreens
Evergreens are typically not candidates for renewal pruning. Instead plants like Japanese Yews, Arborvitae shrubs, Spreading Junipers, and Boxwood can all be pruned by heading back the longest stems back into the body of the plant (to where there is still foliage) - but never cutting them off at the ground level or they will not regrow from those cut stems without foliage on them.
Any specific pruning questions can be directed to our customer service team for help or check out that plant’s #ProPlantTips For Care on its Product Page.
When NOT To Prune
- Avoid renewal pruning too late in the season or the new growth will not have enough time to develop and harden off before the end of the growing season.
- Avoid renewal pruning evergreens since they do not bounce back and regrow like deciduous trees and shrubs.
- Avoid hard pruning any shrub or shrubby tree that has a single stem or trunk. Opt for thinning the crown instead.
- Look out for grafted plants because they are growing on a different rootstock and cutting the plant off below the graft will result in the rootstock growing instead of the desired plant.
- Complete cutback rejuvenation can be stressful on plants if done too late in the season so consider doing so in late winter or early spring before it starts to grow.
Tools of the Trade
Protect yourself and save yourself some time with these tips:
- Large tarp or two to lay down and collect all the trimmings
- Yard waste bags
- A helper, bungee cords, or twine to help hold branches out of the way
- Depending on the size of the job
- Hand Pruners - either anvil or bypass & ratchet for thicker limbs
- Lopping Shears
- Pruning Saws
- Ensure all tools are sharp and sanitized. Sanitize between each cut!
- Long heavy sleeves and thick gloves
- Eye Protection when reaching deep into a shrub to protect yourself from gouging stems
Renewal Pruning After-Care
Give your newly pruned shrubs a little TLC to help them recover the very best!
Water the plant well when needed using the finger test method that entire growing season. Continue right through their first winter if applicable. Provide a nice 3-4 inch layer of Arborist mulch over the root zone of the plant, covering the entire drip line area.
Keep high-nitrogen lawn fertilizer away from your flowering shrub, but instead, use one of our balanced fertilizers formulated for flowering shrubs (only when needed) as an early spring application.
Plant Fountain of Youth
Like a makeover, a Mani/Pedi, or a fresh new haircut, we all walk out of the salon feeling like a million bucks! You can update your ornamental shrubs with a smart renewal pruning job which can transform your landscape overnight. You will extend your plant's life, and enhance its health, beauty, and form - and save yourself a lot of money by not having to remove and replace the plants with Renewal Pruning! Then check out more information about Pruning
here! So do some warm-up stretches, grab a helper and get your shrubs looking and feeling young again with the help of Nature Hills Nursery!
Happy Planting!
