October 9, 2013
One of the questions that people always have at this time of the year concerns pruning back plants that are growing in the yard. Spring and summer bring lots of growth to plants and with the arrival of fall, people think about pruning back plants to get the plants back to a manageable size. The question always is, will pruning in the fall cause any problems.
Let’s start with your flowering shrubs. If you prune back your early spring flowering shrubs, you will be pruning off the flower buds that have formed for 2014. Examples of the early spring flowering shrubs would be forsythia, rhododendron, azalea, Pieris and lilac. These plants would be pruned back right after they are done flowering in the spring.
The trickier part comes when you need to prune back some of the other summer flowering shrubs. Rose bushes could be pruned back in the fall. However, pruning back roses at this time of the year will leave open wounds that will allow the winter wind to pull moisture out of the rose canes. This can lead to winter damage and sometimes the death of the canes. Many of the hydrangeas have formed their flower buds for next year. If you cut them back now, you will get new growth in the spring but you won’t get any flowers.
If you want to prune back plants this fall, it is better to check first to make sure that you are not going to harm your plant.
One of the problems that always creep up in the fall is the yellowing and needle drop of many of the needled evergreens. During the past week, I have had several people come into the store with leaf samples from Arborvitae. The branches are turning yellow on the interior of the plant. Sections of the yellowing leaf are falling off of the plant. We have also had people come in with yellow needles that are falling off of pine trees. All of this is normal thinning out of the plant in preparation for winter. All evergreens will shed some needles and it is generally more pronounced in the fall. It is nothing to worry about unless, in the case of the Arborvitae, the yellowing develops on the outside of the branches.
Another question that comes up at this time of the year is whether or not to fertilize shrubs at this time of the year. As a general rule, shrubs should not be fertilized in the fall until the plants have gone dormant for the winter. At that point, flowering trees and shrubs will benefit from an application of phosphorous. This ingredient in fertilizers will help with root development and it will then be available when plants are setting new flower buds in the spring. Evergreens will benefit from an application of fertilizer once they have gone dormant later in the fall.
Mulching of plants in the late fall is important for your plants. I will get into that in the upcoming weeks.