Shrubs that have grown past six feet require specialized approaches for trimming and shaping, differing significantly from managing smaller hedges. Standard hand tools are no longer adequate for this height, and the operation introduces safety considerations related to working far above the ground. Pruning is necessary to maintain a desired size and to ensure proper light penetration and air circulation throughout the plant’s structure. This encourages dense, healthy growth and prevents lower branches from dying out. Successfully managing these taller specimens requires careful preparation followed by precise techniques for both vertical reduction and lateral shaping.
Essential Preparation and Safety Protocols
Working on tall bushes requires robust safety measures, particularly concerning stability and tool handling. Start by securing personal protective gear, such as thick gloves and shatter-resistant eye protection, to guard against falling debris or snapping branches. Necessary tools include sharp hand pruners for smaller growth, long-handled loppers for branches up to two inches thick, and a pole saw or pole pruner for reaching the uppermost growth.
Addressing the height safely often involves using a sturdy step ladder or, ideally, a platform ladder or scaffolding, which offers a more stable base. If a ladder is used, place it on firm, level ground and never move it while standing on it. Avoid overreaching, which destabilizes the ladder; instead, reposition the ladder frequently to keep your work within comfortable arm’s length. Operating power tools, especially those with long handles like pole saws, requires secure footing when working above shoulder height.
Techniques for Reducing Bush Height
The primary goal when reducing the height of an overgrown bush is to make selective cuts that encourage a strong, natural-looking recovery rather than simply shearing the top flat. This is achieved through a technique called heading back, where an overly tall stem is cut back to a healthy lateral branch or bud pointing toward new growth. When cutting, locate the branch collar—the slightly swollen area where the branch meets the larger stem—and make the cut just outside this area. Cutting to the branch collar allows the plant to naturally seal the wound and prevents dieback of the remaining tissue.
If significant height reduction is necessary, remove no more than one-third of the total plant height in any single season to prevent excessive stress. Removing too much foliage at once can force weak, stress-induced growth or cause lower branches to die off from light deprivation. For extremely tall bushes, this reduction may need to be phased over two or three years, allowing the plant time to recover after each session. Avoid using hedge shears to buzz the top, as this promotes dense surface growth, shading out interior branches and weakening the overall structure.
Shaping and Thinning the Lateral Growth
Once the vertical dimension has been addressed, attention shifts to managing the width and density of the bush through thinning and shaping cuts. Thinning involves removing entire branches, cutting them cleanly back to the main trunk, a large scaffold branch, or the ground, instead of cutting just the tips. This removal of interior branches improves air circulation, which is a major factor in reducing the incidence of fungal diseases, and allows light to penetrate deeper into the shrub’s center.
Tall, dense bushes often become “leggy,” meaning lower branches lose density due to lack of sunlight. To counteract this, lateral shaping should involve tapering the sides, making the bottom slightly wider than the top. This pyramidal shape ensures sunlight reaches the lower foliage, maintaining density from the ground up. Pruning outer branches back to a side shoot or bud directs new growth inward, helping to maintain the desired width and preventing encroachment on nearby areas.
Seasonal Timing and Post-Pruning Maintenance
The optimal time for pruning depends on whether the bush is grown primarily for foliage or for flowers. Most non-flowering shrubs and those grown for structure benefit from major reduction pruning during late winter or very early spring while the plant is dormant. Pruning during dormancy minimizes stress and encourages a vigorous flush of new growth once warmer weather arrives.
For flowering bushes, adjust the timing to preserve the bloom cycle by pruning immediately after the flowers fade. Spring-flowering shrubs set buds the previous summer, so pruning them in late winter would remove the blooms. Following any significant pruning, clear all cut branches and debris from the base of the plant to eliminate hiding places for pests and fungal spores. If substantial foliage was removed, provide a deep watering to help the plant recover and support new growth.