Prune Trees This Winter
This time of year, snow covered bare tree branches can create some eye-catching silhouettes. KUNC Gardener Tom Throgmorton says enjoy the winter landscape and do a little gardening.
Most plants in our western landscapes are leafless for at least five months of the year. Our winter landscapes are dominated by fascinating forms and textures.
The low sun angle accentuates the form of most deciduous trees. Their branching structure stands out against the soft blue sky. Russian Hawthorns are one of my favorites for the winter landscape. Russian Hawthorns have attention snagging, gnarly, twisted trunks. Other trees like Ohio Buckeye and Kentucky Coffeetree, have only a few, stout branches.
Multi-stemmed trees offer special interest during the winter. Their various trunks are more eye catching. New Mexican Privet has distinctive blond bark. Multi-stemmed crabapples can have red to bronze colored bark. The many stems of our native Bigtooth Maple and Wavy-leaf Oak are accented by russet leaves that hang on into the late winter.
Because of these winter silhouettes, most arborists agree winter is the season to prune trees. Leafless trees allow arborists easier access. We can see what we’re doing. It makes our job more efficient.
Trees store energy in other tissues once they lose their leaves. Any injury, like a pruning cut, becomes a priority for the stored energy. Winter pruning gives more time for wounds to close and heal. This is important so wood boring insects can’t easily damage a tree. It’s beneficial to prune American elms and ash trees during the winter months.
New studies are showing that pruning pine and spruce trees during the winter lessens attacks by Mountain Pine Beetle and IPS Beetle. It seems the insects are drawn by the scent of a fresh cut. Winter pruning allows the wound to close over and cuts off the scent before the insects fly in the spring.
Apple, mountain ash and pears should also only be pruned when they’re dormant. They’re all susceptible to fire-blight. Fire-blight enters trees through open wounds. Winter pruning lets the wound close and reduces the risk of fire-blight infection.
Winter interest can be as simple as the texture of ornamental grasses surrounded by snow or as dramatic as the silhouette of an oak tree. Winter form and texture are integral to any design for our western garden. Maintain plant silhouettes by contacting a local, licensed arborist to prune your tree investment.