Not All Plants Will Benefit from Spring Pruning

Not all plants are fans of a springtime trim, so before you grab those pruning shears, it’s important to know which ones to leave alone.

Some plants set their flower buds the year before, meaning a spring pruning spree could accidentally snip away this year’s blooms. Yikes, right?

Take lilacs, for example. These gorgeous, fragrant shrubs bloom on old wood and cutting them in spring can mean sacrificing their delightful flowers. The same goes for forsythia.

If you love those bright yellow blooms that signify the start of warmer days, wait until after they finish blooming to do any pruning.

Another no-spring-pruning candidate? Hydrangeas—specifically, varieties like bigleaf or oakleaf hydrangeas.

These too develop their flower buds on last year’s growth, so a spring haircut can leave them flowerless for the upcoming season. Instead, prune them after they’ve flowered.

When it comes to pruning, having the right tools and knowing proper techniques can make all the difference. Essential tools for pruning include bypass pruners for clean cuts on live branches, loppers for thicker branches, and a pruning saw for even larger limbs.

For precision work, consider using sharp garden shears, and always ensure your tools are clean and well-sharpened to avoid damaging the plants.

Start by identifying dead, damaged, or diseased branches—and remove these first to encourage healthy growth. When cutting, make clean, angled cuts just above a bud or where the branch meets the main stem.

Angled cuts help water to run off, reducing the risk of rot. For shrubs or hedges, shape the plant gradually, stepping back periodically to assess the symmetry and overall appearance. Avoid over-pruning, as too much at once can stress the plant.

With the right tools and careful techniques, you’ll end up with flourishing plants that reward your effort with vibrant growth and blooms.

Exceptions to the Pruning Rules

When dealing with flowering plants: Some plants, like lilacs or forsythia, bloom on old wood. Pruning these plants in the late fall or winter can remove their flower buds for the next season. Instead, prune them right after they finish flowering.

Seasonal timing for specific plants: Certain trees and shrubs, such as maples and birches, tend to “bleed” sap excessively if pruned in late winter or early spring. For these, it’s best to prune during their dormant period or mid-summer.

Plants sensitive to heavy pruning: Some species, like hydrangeas or magnolias, can be severely affected by over-pruning. Always research the specific needs of the plants in your garden before making significant cuts.

Diseased plants under certain conditions: If a plant is suffering from a contagious disease, pruning during wet or humid weather can exacerbate the spread of the infection. Wait for dry weather conditions to prune carefully.

Evergreens and conifers: Many evergreen shrubs and conifers do not respond well to cutting into old wood. Be cautious and avoid cutting back beyond the green growth, as these plants may not regenerate foliage.

And don’t forget fruit trees like cherries, as well as flowering trees like magnolias and dogwoods. These trees are best left untouched in spring to ensure their blossoms remain intact.

If in doubt, do a quick check to find out whether your plant blooms on old or new growth—this small effort can save your garden from an accidental flower famine.