As the snow melts, many Ontario homeowners are eager to head out with their shears. However, pruning the wrong plant at this time can ruin your spring display or leave your trees vulnerable to disease.
To help you out, I’ve created a guide on what you should and shouldn’t prune in spring to keep your garden thriving. Of course, if you’re still not sure, we are a phone call away and would happily assist!
The Golden Rule
If it blooms before June, don’t prune!
That includes:
- Spring-Flowering Shrubs & Trees
These plants flower on “old wood.” Wait until immediately after flowering to tidy them up.
Lilacs & Forsythia: Their buds are already set and ready to pop.
Magnolias & Serviceberry: Pruning now creates messy wounds and removes the blossoms.
Azaleas & Rhododendrons: These are spring stars; leave them be until they finish their show.
Bridal wreath spirea: Unlike summer spireas, these arching white beauties bloom on old wood. - The “Sap Bleeders”
Trees with high sap pressure in early spring will “weep” profusely if cut. This attracts pests and stresses the tree.
Maples & Birches: Best pruned in late summer once leaves are fully out.
Walnut Trees: Avoid spring cuts to prevent heavy sap loss. - Perennials to Leave Standing
While many perennials need a spring cut-back, some are better left alone until they finish their early-season show.
Peonies: Don’t disturb them early; let the foliage grow to support the heavy blooms.
Hellebores (Lenten Rose): These are often the first to bloom. Only prune away last year’s tattered, brown leaves to show off the new flowers.
Bleeding Heart: Leave these alone until the foliage naturally yellows and dies back later in the summer. - Tricky Hydrangeas & Vines
Not all hydrangeas are equal. If you aren’t sure which one you have, wait!
Bigleaf (Mophead) & Oakleaf hydrangeas: These bloom on old wood. Spring pruning = zero flowers.
Group 1 & 2 Clematis: Early bloomers and large-flowered hybrids set buds on old stems. Avoid a hard spring cut.
The Fruit Tree Exception
Apples & Pears:
A question we get every year: “Should I prune my apple tree now?” The answer is yes, but only while they are still dormant.
In Ontario, you want to finish pruning apples and pears in late winter or very early spring (usually by late March).
Why? Once the blossoms emerge, pruning increases the risk of fire blight, a common bacterial disease in our region.
Stone Fruits (Peaches & Cherries): These are different.
Prune peaches just as buds swell so wounds heal fast.
Prune cherries in late summer after harvest to avoid canker.
Now you are probably wondering, what can I prune in spring? Early spring is the perfect time to rejuvenate these plants as they prepare to grow on “new wood.” Here’s your guide on what to prune now and how to do it.
Perennials safe to be pruned in spring:
Summer-blooming spirea: Varieties like ‘Goldmound’ or ‘Anthony Waterer’ love a spring haircut to stay compact.
Panicle & smooth hydrangeas: ‘Limelight’ and ‘Annabelle’ bloom on new growth. You can cut these back quite hard in March or April.
Group 3 clematis: Late bloomers like ‘Jackmanii’ should be cut back to about 12 inches from the ground now.
Ornamental grasses: Cut these back to 4–6 inches before new green shoots appear.
Rose bushes: Most shrub roses should be pruned in April before they leaf out.
Perennial Checklist (Cut Back Now):
Clean these up before they start pushing new growth.
Hostas & daylilies: Remove the mushy, dead foliage from last year.
Echinacea (coneflower) & black-eyed Susans: If you left them for the birds in winter, cut the stalks back now.
Asters & sedum: Trim back old stems to make room for fresh green mounds.
Butterfly bush: Prune hard in late spring once you see new buds.
Quick Professional Pruning Tips:
Remember the “Three D’s”: You can remove dead, damaged, or diseased wood at any time of year.
Sanitize: Clean your pruners with rubbing alcohol between plants to stop the spread of garden diseases.
Don’t overdo it: Never remove more than 25% of a plant’s total canopy in one go.
Need a hand?
If you are staring at your shrubs and aren’t sure where to start, we’ve got you covered. We’re happy to stop by, take a look, and take the guesswork off your plate so you can just enjoy the view.
