Pruning Creates or Maintains a Shrub’s Natural Form
Topiary is a delight. Controlling nature is an impressive show of power. Too much power corrupts, according to Lord Acton. I will paraphrase his famous words—Put down your electric shears.
Good pruning is like a good haircut. There are times when a dramatic, Avant guard, blunt cut is exciting, but most trimming should look natural. The best way to prune is to clip away anything that challenges a plant’s natural shape, and hide the cut deep within the remaining foliage. Limit the tortured, manipulated geometric shapes to theme parks and special display areas. Pruning shrubs into unnatural shapes brings decline, cuts off potential blooms, and is inappropriate for every setting (except a formal parterre garden).
Avoid the temptation to create green balls and trapezoids out of foundation evergreens. It’s tacky. I’ll leave it at that. Professional landscape designers create maintenance specifications that prohibit the use of electric shears for this very reason. Look at the excellent example of specialty shearing in the photograph. Everything tapers to a wider base, so sunlight can reach all the branches. This topiary menagerie has lasting quality because the professional pruning crew understands plant material.
The best maintenance pruning happens when the landscape designer chooses fitting cultivars that mature to a suitable size where they don’t require crown reduction. The best landscape designers space shrubs to either highlight individual, natural forms or allow a larger mass of interwoven branching. Either way, the worst thing a maintenance crew can do is to stub-cut the growing branches with visible header cuts. Again, prune away only those branches that challenge a plant’s natural shape, and hide any cuts deep within the remaining foliage. This is called the deep cut pruning method, and you will see it specified in good maintenance work plans.
Pruning should happen when a shrub is dormant. The exception would be flowering shrubs that bloom on old wood. They should be pruned immediately after blooming, to allow the subsequent growth to set new buds. Better yet, leave flowering shrubs that bloom on old wood alone and unmolested in locations where they can spread out wide and tall, according to their natural habit.
Columnar evergreens need particular pruning care. They have been genetically bred to shoot stems upward vertically, but they forget the instructions sometimes. When you see a columnar shape with an errant limb heading in a horizontal or weeping path, cut it back to a growing node facing upward to direct new growth back in line.
There are two options for shrubs planted in the wrong place where they have overgrown their spot and require constant pruning. Option one is to severely cut the shrub back to about six inches from the ground every few years. Using the haircut analogy, it’s like shaving someone’s hair back to an inch or less—a convict cut. It takes time to regrow, but it keeps branches away from paths and windows. Option two is to remove or relocate the shrub to a better place. I have never, in all my years of professional landscaping, heard anyone say, “I wish that too-tall Holly was still blocking the windows of my house.” An empty patch of mulch is better than an overgrown foundation plant.
Good pruning starts with good design, just as a great haircuts happen at the best salons. The maintenance cuts need to respect the original design plan. Electric shears are tools that should be left to the experts, for obvious reasons! Hand clipping to maintain natural growth is the best way to develop a legacy landscape. A venerated design deserves a great cut.