Winter pruning and trimming is a lot easier if you spread the work over our short two-month dormant season which begins in late November and ends in late January. Most deciduous trees and bushes can be safely pruned after leaf fall. The first trees to lose their leaves in November are Chinese pistache, liquidambar and sycamores. Hydrangeas are among the first deciduous bushes to lose their leaves; roses will bloom all winter long unless all new growth and buds are removed and the leaves are stripped in November when they can then be pre-pruned (very helpful if you have a lot of roses). Japanese maples and crape myrtles are generally the last trees to lose their leaves; they can be pruned in late January. Buddleja (butterfly bush), the sages, and spirea are cut back hard in late winter when they are finally dormant.
Mature trees that have been well-trained over the years seldom need much pruning. Take a close look at your mature landscape trees in the next week or two and make notes of dead branches and any limb dieback before all the leaves fall. Our trees are still suffering the effects of the four years of severe drought and this last, very hot summer. Trees that are over 15 feet high legally must be trimmed under the supervision of a certified arborist. Even if you’re planning on pruning your smaller trees yourself, it’s a good idea to get an expert opinion from an arborist, especially if your small tree has large dead limbs. Rebalancing and restructuring trees that have lost major limbs is a real skill.
Pruning any tree or bush begins with clearing out the middle of the canopy or branch structure – not by whacking at the branches on the exterior. Start by sticking your head into the interior of the canopy and identifying which branches are crossing through the interior space or are rubbing against other branches. Those branches should be cut back to the juncture of the branch and the trunk or a main branch. Then remove any suckers growing at the base of the tree or bush and any water sprouts that grow straight up along the trunk. These first pruning cuts may actually be all that is needed.
If your tree or bush needs more work, it’s best to do a little research first on proper pruning techniques for your specific tree or bush. The Fresno County Master Gardener’s website, www.ucanr.edu/sites/mgfresno, has a series of how-to-prune young trees videos produced at UC Davis (listed under Landscape Tree Care, then under Training Young Trees). The videos give good general explanations of terms and techniques for beginners, but taking them into the garden to follow as you prune isn’t really practical. Three good books on pruning with great step-by-step illustrations are published by DK Press, www.dk.com/us: “Pruning and Training” ($23.95) “Pruning Plant by Plant” ($14.95), and “American Horticultural Society Pruning and Training” ($22.95), the most advanced and comprehensive guide of the three.
One of the best pruning guide books is unfortunately out of print, but used and new copies are often available online. Ortho’s “All About Pruning” ($11.95) has excellent, detailed, well-explained illustrations, especially for rose pruning.
Send Elinor Teague plant questions at firstname.lastname@example.org.