The Best Way To Prune Hedges, Flowering Bushes, & Broadleaf Evergreens

Hedges: Sheared hedges need to be clipped with a sharp hedge shears electric tool every time new growth reaches 2 or 3 inches; otherwise, the hedge soon looks ragged. Do the job correctly; stretch a guiding cord along both upper edges of the hedge so the surface is  absolutely level and the edges square. Move the cords to the bottom and level the sides, A well-sited hedge of vigorous leafy plants such as privet or barberry can be trimmed with vertical sides and hold its foliage right to the bottom. But it is far better to bevel the hedge so the bottom is half again as wide as the top. This allows light to reach clear to the base of the
hedge on both sides, and leaves will go all the way down.

If all the plants in a deciduous hedge are alive but perhaps weak and bare at the base, the hedge can be saved. For one season cultivate along the sides and fertilize in late winter and mid-spring. The following spring before buds begin to break, cut the hedge to the ground, or at least to very short stubs. As new growth develops, let the shoots reach 10 inches or so, then cut them back to half. Keep this up all summer, gradually building the hedge back to a dense barrier. It will take a few years to get it up to waist height. Needle and broadleaf evergreen hedges that have deteriorated should be replaced.

Flowering Bushes: Prune your shrubbery throughout the year and you never will be faced with a massive overhaul job. In late winter bring in branches of forsythia, Japanese quince, bridal-wreath spirea and others to force for blossoms; take these branches where the plant is out of shape or crowded. In summer bring in flowering sprays the same way. When the spring rush is past, with a sharp, narrow spade remove almost all of the underground sprouts that come up around the base of older shrubs. At the same time, watch for those long, unbranched shoots that spring from the base or low in the older branches.

These still will be tender and soft; cut them back to one or two leaves (or pairs of leaves, if the foliage is opposite). Come back in a month and pinch again. In the dead of winter, with your narrow little pruning saw take out one-fourth or less of the oldest canes in bushes that are more than five years old. This keeps new wood coming on. If you have time, nip off spent flower heads as flowering shrubs go out of bloom - a nice idea with valuable rhododendrons and the newest lilacs, but impossible in most gardens save with a few specimen plants.

Broadleaf Evergreens: Hollies, Euonymus species and cultivars, mahonias, aucuba and the cherry-laurels (to name a few) are vigorous broadleaf evergreens that may be trimmed freely. Theoretically, these should be pruned as necessary to keep them dense and in good health, just as the spring growth hardens. And it is a good idea to do a fair  amount of pruning and pinching at that time. But think of the value of the cut-away branches for home decorating.

So long as the temperature is above freezing, you can go out quite safely in late November or early December and do a pruning job aimed at properly shaping the plants, but with an eye toward handsome sprays for holiday decor. Try to make all cuts face inward, so the garden is not marred for the rest of winter by exposed, white patches of bare wood. Less vigorous broadleaf evergreens are best pinched, not pruned at all, or rarely. As rhododendrons and semi-evergreen azaleas go out of flower and the new shoots break beneath the spent blossom cluster, nip out this old flower head and pinch the new shoots below where they have made three or four leaves. This will prevent leggy overgrowth, and it limits pruning to a once-a- year proposition.

Azaleas may be pruned almost any time, as they are well furnished with latent buds on all old stems. But for the sake of next year's bloom, prune in late spring or early summer. Very old bushes should be brought into prime condition by fertilizing and mulching prior to heavy pruning intended for renewal.