Bonnie Nowicki
With spring just around the corner, perhaps you are asking yourself what landscape plants you should be pruning or trimming now. Here in the low desert, it is possible to prune any time of the year. But pruning outside the recommended guidelines may diminish blooms the following year. It is appropriate to remove dead branches and suckers from the lower trunk anytime. Remember, every cut you make opens a wound on the plant, making it vulnerable to disease and pests, so make sure you have a good reason to prune.
Before you make the first cut and to prevent over-pruning, identify your specific goal or purpose for pruning. Have a plan and base your decision on achieving it with minimal pruning cuts. Inspect the structure of the tree or shrub and identify the branches to be removed. Determine the desired shape and openness of the specimen prior to cutting. It’s helpful to tag the branches with bright-colored tape or yarn and step back to see how the plant will look after pruning.
For non-native, deciduous trees, conifers, and summer-blooming shrubs, pruning should be done during winter dormancy (January) prior to new buds appearing. For spring-blooming shrubs where the flowers appear on last year’s growth, like fairy dusters, sennas, and rosemary, pruning should be done after blooming is complete. If you want dense branching for shrubs, it is important to cut back the tips. Native trees such as palo verde and mesquite should be pruned in May through early June. They naturally grow with multiple branching and need less pruning. If pruning to encourage new growth, remove the branch at its point of origin (where it attaches to its parent branch or trunk) or cut back to a bud facing in the direction that you want future growth to expand.
A proper basic pruning cut that leaves plant tissue to seal off the wound is made along a straight line connecting the “branch bark ridge,” which is a raised furrow of bark found on the top side of the branch, and the outer edge of the “branch collar,” which is a raised furrow of bark on the underside of the branch. If you have old, leggy shrubs, a rejuvenation pruning will work well. Before plants start growing in spring, cut all branches to within one-half to one foot above the ground. New branches will grow vigorously. This procedure benefits oleander, Texas ranger, spirea, and butterfly bush.
Please remember to remove dirt and pathogens from your pruning shears with Pine-Sol or alcohol. If you have a major tree-trimming job, consider calling a professional arborist. Happy gardening!