Homes throughout the Rogue Valley and elsewhere are being swallowed up by rhododendrons and other evergreens that haven’t been pruned properly. There is a vicious myth that evergreens don’t require pruning, unless they are topiaries.
So. Not. True.
While evergreens of both the needled and broad-leafed varieties generally require much less pruning than deciduous trees and shrubs, pruning they DO need.
The same general rules that apply to pruning other plants also apply to evergreens. Remove any dead or diseased branches, making clean cuts with a sharp saw or pruner to promote good wound closure. Also remove any misplaced branches, such as ones that cross other branches and rub against them.
Shorten a stem or branch if you want to encourage more branching and bushy growth. Remove selected stems completely, right to their origin, where growth is too congested and you don’t want any regrowth.
To drastically lower a shrub’s height, cut a few larger stems back to their origin down within the plant or cut vigorous side shoots originating low and within the plant.
If you want your plant to have thick foliage, prune some upper branches to keep them from shading the lower ones. This means trimming any evergreen hedges so that they are narrower at the top than at the bottom. Shorten some of the uppermost steps of evergreens to let the branches below continue to creep outward and thinning out the tops of large shrubs or trees.
With a few exceptions, the best time to prune evergreens is late winter or early spring, just as your plants are thinking about getting a jump on growth for the coming season. To get the best possible show of color, prune early-flowering evergreens immediately after the bloom ends in the spring.
Rhodies and laurels require very little pruning, but allowing them to grow gangly and not providing the proper maintenance will give you unattractive plants with ever-decreasing blooms from year to year.
When your plants are young, shortening the stems to induce branching will make them grow more densely. With Rhodies, the best time to do this is mid- to later winter. Look for shoots terminating in four pointy buds, and then remove the center bud. Don’t touch any of the fat buds, which will turn into blooms later. This middle pointy bud is usually the one that will sprout, while the others remain dormant. Plucking this on encourages the side shoots to grow.
With older Rhodies, be mindful of how drastically you shorten branches. The older wood may not have viable buds to sprout into new shoots. If you cut back holly, heather, heath or bearberry to old wood, you’ll be left with nothing but dead stubs. This caution also applies to some kinds of Rhodies. If you have to shorten an older broadleaf that could be blocking your living room window, do so gradually. A few stems at a time, a few each year, to avoid shocking the plant.
With a little time and attention to detail, your evergreens and Rhodies will be the pride of your gardens.