Some handy advice for pruning evergreens

EVERGREEN plants require less pruning than deciduous plants, but do need some pruning. This is dramatically attested to at windows doorways of homes on engulfed by rhododendrons, junipers, and yews. Besides keeping evergreens to size, pruning also can be used to make plants’ foliage denser.

Let’s assume you have a narrow-leaf evergreen in need of drastic pruning. Before bringing your saw or lopper even near that plant, figure out more specifically what kind of plant you have. Pines, firs, and spruces will not send out new growth from leafless wood. So any pruning on these species must be only as far back into the plant as there are leaves. Just how far you can cut will vary with the species because white pines, for example, retain their needles for three years, while Scotch pines retain their needles for five years.

Thuja (arborvitae), juniper, hemlock, and yew are narrow-leaf evergreens that can regrow new branches from old, leafless branches. Therefore, regrowth can be expected even when these plants are cut back severely. I stood by the courage of my convictions years ago when I offered to renovate my father’s overgrown, 25-yearold yew hedge. In two hours, the row of neat, lush greenery was transformed to foothigh, dark, gnarled, leafless stubs. The hedge looked ragged the following season, less so the next season, and after another couple of years had finally begun to fill in while no longer threatening to overwhelm the patio it surrounded. Thuja, hemlock, and juniper can be expected to respond similarly, though not quite as well, to such drastic cutting.

The kind of plant also must be considered when the objective in pruning is to make a plant more dense. Pines, spruces, and firs should be pruned while the shoots are expanding in spring, but before these shoots fully unfurl their needles. Snap the new shoots in half by hand, in so doing awakening the otherwise dormant buds at the bases of these shoots. The result: a denser plant.

Also prune thuja, juniper, hemlock, or yew in spring before growth, but in this case before growth commences. For a formal appearance, shear the plants; for a natural appearance, snip off individual branches with pruning shears. A follow-up pruning in midsummer, or even a couple of followups, will keep plants even neater.

Cutting branches off broadleaf evergreens, such as rhododendron and mountain laurel, should be avoided whenever possible. Regular, annual pruning consists primarily in removing faded flowers, taking care not to damage buds at the bases of the flower stalks. This pruning causes buds to initiate growth sooner, increasing the potential for flowers the next season. Occasionally, a wayward branch on a rhododendron ruins the form of a plant, or, after years of neglect, a plant creeps up to and then in front of a window. In these cases, some branch pruning is needed. Do this right after flowering. Broad-leaved evergreens will regrow shoots from old wood, so branches can be cut back hard if need be. If a whole plant needs renovation, cutting should be spread over the course of a few years.

Pruning alone shouldn’t be relied upon to keep either broad or narrow-leaved evergreens to a desired size or shape. Varieties of these plants exist whose natural growth habits range from low and spreading (the “Ward” variety of yew and the “Blue Rug” variety of juniper, as examples) to sharply columnar (“Harfield” yew and the “Canaertii” juniper), with all shapes and sizes in between. Ideally, pruning should do no more than support the natural inclinations of these plants.

(For more details on pruning evergreens — and most other plants — see my book, “The Pruning Book,” available from the usual sources as well, signed, directly from me at www.leereich.com/ books.)

Any gardening questions? Email them to me at garden@leereich.com and I’ll try answering them directly or in this column. Come visit my garden at www.leereich. com/blog.

CHICOPEE Composting program

The Chicopee Public Library, 449 Front St., will present “Composting 101” on April 20 at 6:30 p.m. Learn all about the ins and outs of composting with Kaitlyn Mitchell from the Center for Ecotechnology. What is