The Kindest Cut: Pruning in the Winter
Winter is the best time to prune—especially if some of your trees have gone a few years without being pruned and will require that a lot of wood be removed. When plants are dormant, they are better able to cope with the removal of a lot of branches, as may be needed when properly shaping and thinning out a tree or large-growing shrub.
For most of Santa Fe County, the pruning season begins in late December and extends through mid-March. Plant dormancy is affected by temperatures; a mild winter brings them out of dormancy earlier. A cold, snowy winter extends dormancy. With luck, this year we’ll have a long pruning season!
What to Prune
Shade trees, flowering trees, fruit trees, grapes, Butterfly Bush, flowering vines (except Wisteria which should be pruned after blooming).
What Not to Prune
Spring flowering shrubs like Lilacs, Snowball Bush (Viburnum), white-flowered spirea, mahonia, mock orange (Philadelphus), flowering almond, shrub/native roses, Buddleia alternifolia, and other shrubs that flower in April and May should be pruned after they finish blooming. June is the best time to prune these spring bloomers.
Be patient; wait until early May to prune roses. They will be in leaf and actively growing, but that’s OK for roses. It's too early now to cut back your perennials and ornamental grasses.
Evergreen trees (pines, spruces, fir, and other conifers) have their own pruning methods that are, in part, different from typical deciduous trees and shrubs. Like deciduous trees/shrubs, we prune evergreen trees in winter/early spring to get rid of crossed interior branching (thinning) and to shape the tree if it starts to grow in a distorted way. But differently from deciduous trees/shrubs, But pruning evergreens to control their height is done differently than deciduous trees and shrubs. To keep evergreens more compact and densely branched, we do so by cutting/snapping off the tops sections of the candles (see photo below). See blog and video.
Pruning to Thin and Shape Evergreens
This is best done during the winter months if the thinning of interior branches are extensive. Removing just a few can be done during the spring and summer months as well.
These can be pruned or sheared during winter dormancy or during the growing season. But remember, if you shear or cut back the juniper to brown wood, it won’t re-grow new green shoots. Be sure there is green growth below your cut to keep that branch actively growing.
Some General Pruning Comments
Pruning paint/pruning sealer – don’t use it. Leave cuts open to the air so they can heal properly. Covering a cut with a waterproof pruning sealer or paint will trap moisture and possibly cause fungal or bacterial disease.
For more pruning information
The New Mexico State University has published numerous publications through the Agricultural Extension Service. Here are a couple (of many) publications on the subject.
Text and Photos By David Salman © All articles are copyrighted by WATERWISE Gardening, LLC. Republication is prohibited without permission