Tips for trimming spring flowering shrubs
Last week, I told you all I was worried that if I returned home too late from Florida I would miss spring time in the mountains. No one should miss the arrival of spring in the beautiful Catskill Mountain region, if it is at all possible.
Well, as it turns out, it was still pretty wintry up here in the hills right up until May 2, when it suddenly turned into summer. Last Sunday, April 29, the high temperature for the day was below 40 degrees and more than 4 inches of snow fell at my house!
Today (Wednesday), May 2, it hit 90 degrees!
This newly arrived warm weather has many people happily working and playing outdoors. Please be aware that disease-carrying ticks are very active right now and even just spending a few minutes walking in the woods or working in the garden can result in you getting many, many ticks on you and that can lead to serious problems such as Lyme disease and other bacterial and viral diseases. Some of these tick borne illnesses can even be fatal. I strongly suggest that you spray your clothing, shoes and outdoor gear with a product that contains permethrin. This repellent also kills ticks on contact, but it should never be applied to your bare skin. It is also highly toxic to cats, so do not use it on cat bedding or places where kitty hangs out. The past two days, I have spent about 12 hours in tick-infested woods and at least three hours of that time laying on the bare ground, napping. I sprayed my clothes with permethrin and so far I have not seen a single tick on me. A friend of mine counted more than 50 ticks on his clothes after a five-minute walk in his woods. This is not at all unusual, I am sorry to report.
The sudden onslaught of summer-like weather caused many spring flowering trees and shrubs to burst into bloom, almost overnight. Actually it happened even faster than that. This morning as I drove to my turkey hunting spot, I noticed that many of the forsythia bushes were just starting to show some yellow color on the buds, but, by 3 p.m. this afternoon, they were fully open. I drove to Catskill later on and it seems that every place I looked there were forsythia bushes in full bloom. I don’t recall ever seeing such a spectacular show of one particular type of shrub at one time.
Of course, as I drove into a much warmer zone in the Hudson River Valley, there were lots of other beautiful spring flowering trees, shrubs and bulbs showing off their stuff as well, but nothing compared to the yellow display of the plant whose name we all mispronounce. It is properly pronounced “Forsigh-thia, not “For-sith-ia”.
A reader from Ulster County recently asked why her 20- or so-year-old, forsythia bush had been flowering less and less the past few years and she wondered if a drastic pruning was in order. In general, it is a good idea to periodically prune back all spring flowering shrubs pretty severely to rejuvenate them. A general rule of thumb is to remove about onethird of the total growth each year at ground level to “shrink” the bush and cause it to flower better.
In the case of forsythia, they are very tough plants
and I told her she can cut it back much harder than that without killing it. I did notice that some of these shrubs only had the top part of the bush flowering, while the bottom was bare wood. These plants had been “topped” last year and since forsythia flowers are produced on the previous season’s growth, only that new growth had flowers.
The proper way to prune forsythia and many other spring flowering shrubs is
to remove some of the oldest stems at ground level each year so that the entire shrub is “replaced” with new growth arising from the ground over the course of three or four years, with no stems being much older than three years. This ensures a more uniform appearance and flowers all over the plant, not just at the top. Forsythia can be trained into a hedge if desired, but, unless the ground level pruning is carried out faithfully, they will not look so good. The other reason why the bush may not be flowering profusely is because, over a period of 20 years or so, the trees and other plants growing nearby may be shading the bush now and most spring flowering shrubs prefer to be in full sun.
Many people never even notice this is happening, since it is so gradual. This is a very common reason why lilacs fail to bloom as well. The best time to prune all spring flowering shrubs is right after the flowers fade, which for most of us is right now.
Bob Beyfuss lives and gardens in Schoharie County. Send him an e-mail to rlb14@cornell.edu.