Winter is the ideal dream time for cold-climate gardeners, but it’s also a perfect time to review good gardening practices and increase your gardening knowledge. For this Winter Review we’ll examine winter pruning.
Take advantage of sunny late-winter days by heading outside to complete some winter pruning. Shrubs are dormant during winter, which makes it the perfect time for pruning damaged, dead, or diseased branches.
Choose your pruning targets carefully, though. Shrubs that flower on last season’s growth – think lilac, forsythia, pieris, mountain laurel, rhododendron – and flower in early spring are best pruned shortly after they finish blooming. Prune these during late winter and you remove much or all of the upcoming blooms.
Shrubs that bloom on new growth, such as butterfly bushes, cotoneaster, and red- and yellow-twig dogwood, should not get a pruning visit until early spring. Wait until new growth is just beginning to show and remove only winter-killed or damaged branches, or those causing an unbalanced or unattractive form. If you are looking to prune hydrangea, first know what type of hydrangea you have, then seek the advice of a knowledgeable professional rather than risk losing upcoming hydrangea blooms.
Winter prune diseased or dead branches when cold still has a good hold on the weather but a few sunny, warmer days start breaking through. If heavy snow has split or broken a branch, it doesn’t matter when the shrub or tree blooms. The damage limb must be removed.
Branches scarred by rubbing against another object – specifically crossed-branches – are easily identified when shrubs are bare. Crossed branches lead to chaffing, leaving wounds that invite insects or disease. Prune crossed branches to maintain your shrub’s health.
Branches that are too close together, such as those to the right, should also be pruned. While not yet causing damage, they will rub against each other when winds blow. Jagged stem ends can also be pruned at this time.
Pay special attention to suckers – thin, spindly growth often emerging from the base of the shrub. Be sure to remove any suckers growing from below the base union – usually a fatter section at the base of the plant where a graft was added to rootstock – or from beneath the soil of a grafted shrub. Suckers growing from rootstock have characteristics of the rootstock, rather than the grafted and more desirable section of the shrub.
In non-grafted shrubs, remove suckers that are not needed to replace any old or damaged branches. If you plan to keep the shrub, a few selected suckers can be left to grow and become replacement branches for larger branches that had to be pruned out.
Pruning is a necessary part of maintaining shrub and tree health, but it can also be a very confusing part of garden maintenance. Learn more by reading Pruning & Training by Christopher Bricknell and David Joyce, or seeking web-based tips from a local state extension office. When in doubt, or when a favorite shrub has grown beyond your pruning abilities, seek pruning or replacement advice from trusted, well-trained garden professionals.