Winter is a great time to prune many of your deciduous trees and shrubs. Without the leaves you can easily see the structure of the plant, including crossing, broken and damaged branches. Pruning some branches now will not only help to reduce damage from winds, storms and heavy snow but also improve air circulation and promote more new growth come spring. Here are five things you should know about winter pruning before you start.
CHECK THE WEATHER
Winter pruning should be done on days when temperatures are above freezing and there is no snow or ice on the branches. Drastic temperature fluctuations are stressful to plants. Before you start pruning, make certain to check the extended forecast as well. If temperatures are expected to drop significantly, it would be best to delay pruning until they level out above freezing again.
DID YOU KNOW?
Trees in the Quercus (oak) and Ulmus (elm) family should only be pruned in the winter while insects are dormant to prevent the spread of diseases, such as Dutch Elm Disease and Oak Wilt.
KNOW WHAT TO LOOK FOR
With any tree or shrub, start by removing damaged and broken branches. Removing these will help prevent unwanted pests and diseases. Removing double leaders on trees with a strong central structure, suckers and water sprouts will invigorate spring growth. Crossing branches that are rubbing or growing inward on trees and shrubs should also be removed. This will improve air circulation and prevent rubbing where pests and disease can enter. Once all of those have been removed you can look at the overall shape of the tree or shrub and prune accordingly to achieve a uniform growth structure. We recommend that you contact a professional such as Bartlett Tree Experts or Steve Piper & Sons to trim trees with a tall canopy or to remove hazardous branches (branches encroaching on power lines and structures). Feel free to email us if you need additional referrals.
USE PROPER PRUNING TECHNIQUES
Always start with sharp, clean pruners. For smaller twigs and branches under 1/2” inch in diameter, cut back to an intersecting branch that faces outwards to prevent growth towards the center of the plant. Make clean 45 degree angle cuts close to the intersection. Twigs have special cells in this area so that when cut, the wound will seal itself. By leaving too much of the stem behind it becomes an entry point for insects and disease. The same is true for wider branches only they have developed an area of thick bark around the base of the branch called the collar. It’s important to cut these branches flush with the collar and not the trunk as the collar will aid in the natural healing process. Eric, one of our tree specialists, demonstrates how to prune larger branches.
DID YOU KNOW?
Acer (maple), Betula (birch), Fagus (beech), and Carpinus (hornbeam) families have copious sap flow, known as ‘bleeding’ when cut. Avoid pruning saplings or any large branches from these trees until after the foliage has fully emerged.
KNOW WHEN YOUR FLOWERING PLANTS BLOOM
Trees and shrubs that produce spring flowers (blooms before June 15) should not be heavily pruned in winter. Many spring flowering shrubs only bloom on old wood, meaning flower buds are set on last year’s growth, which is difficult to identify during winter dormancy. It is best to wait until after they flower to prune these plants. Woody plants that bloom in summer will benefit from winter pruning before spring growth begins. While most hydrangeas bloom in summer, many varieties produce blooms on old wood and should not be pruned until new growth appears.
DID YOU KNOW?
You can force early spring buds indoors. Forsythia, Quince, Cherry, Magnolia, Redbud, Pear, Crabapple, Pussywillow and even some Maple trees can produce buds indoors when forced. Cut a few branches that are less than 1/2” in diameter and they will come out of dormancy in a few weeks in a vase of warm water.
SIGNS OF ANIMAL DAMAGE
Animals can do significant damage to our trees and shrubs in a very short amount of time. You may find clean cuts made by rabbits and jagged edges made by deer foraging for food during winter. Young bucks will also rub against tree trunks to shed their antlers, which can do significant damage to trees in winter. Pruning animal damage in winter will help prevent insects and disease. To protect your plants from further damage, use wire fencing with mulch for smaller plants and a light colored wrap around tree trunks.
Rabbit damage on a shrub.
Chicken wire can be used as fencing.
Tree wrap to protect young trees.
QUESTIONS?
If you have questions about winter pruning or any other plant related concerns, we are here to help. Email us or call us with your garden questions. Naperville: 630.355.4000 or Aurora: 630.820.8088.
