There's a method of controlling shrub size and keeping flowers that gives an overall natural look.
There is a method of controlling shrub size and keeping flowers that gives an overall natural look. Briefly, we start the shrub on what I will call a recycling program. This method works on all shrubs. In fact, the more prolific the natural suckering, the better. This is what we are going to take advantage of—a shrub’s ability to grow new shoots after the stimulation of pruning out a percentage of its old branches.
Any eight-year-old shrub, pruned little during that time, will be a collection of branches whose ages vary from one to eight years old. It will be the old guys—the eights, sevens and six year-olds, that are outgrowing the space allotted or conceived, the ones that are reaching out to the point where the visual effect is impaired.
Shrub recycling work is best done in spring or fall, when you can see the structure without the leaves, leaving the plant untouched during the growing season. Using a hand saw or loppers, remove some or all of the old guys. Once these are removed, the shrub will look different. You might be done. Stand back and look. With a little touch on the sides, a bit of polish, this year’s work is done. This means that you have room in that spot perhaps for a six-year-old shrub of that variety.
Be patient. Let the shrub have its turn, you just had yours. Let one year go by, leaving the shrub to recover from the pruning. A year later from your spring or fall pruning, let’s inspect. The six-year-olds are now seven and there are lots of new shoots. Can you live with it another year? No, six years old seems to be what I prefer.
Great, let’s prune. Because there are so many small one-, two-, and three-year old shoots, let’s thin some of those, but not all. Any areas of the root crown that are overly thick with new shoots can be thinned. Use your Felco secateurs for this and cut to ground level.
The reason for thinning some of the smallest shoots is that we do not need them all. Those that we leave will be needed later. They are still producing energy for the plant.
Let another year go by and repeat the entire pruning cycle. Prune out the old guys, do some thinning of the overabundance of youngest shoots, and leave everything else alone.
Six years after initiating this process, we have done one complete recycle sequence. Now the old guys are the youngest shoots we left six years ago. None of the original shoots or branches remain. I have decided that, with this species in this place, a six-year-old shrub works. It looks good, has a natural form, flowers on the oldest branches, and keeps me occupied. Guests looking at this beautiful plant will never know what went into its creation. It doesn’t look pruned; it fits and looks great. And it is pretty much completely under control.
In theory, this practice will work for all shrubs. If the shrub doesn’t seem to be keeping up to this much pruning, try taking a year off. These are guidelines, not hard and fast rules.