What kind of shrubs do you have? Is shearing the best way to manage them?
SHEER MADNESS
http://www.plantamnesty.org/shearmadness.htm
The overuse and misuse of sheared shrubbery is one of the most common form of landscape mismanagement. Sometimes shearing shrubs is considered a matter of taste and sometimes it is not. Selective pruners refer to oversheared shrubs as "green meatballs." "hockey pucks," and "gum drops"; they spoof sheared landscapes as "tombstone" or "lollipop" yards and generally lament the presence of ubiquitous "poodleballing." I call it "shear madness."
To the novice eye a sheared yard looks tidy and interesting. To seasoned selective pruners, a sheared yard seems pretentious and betrays an ignorance of good pruning techniques. Whereas tree topping is a crime against nature, poodleballing is regarded as the hallmark of bad taste in gardening.
Shearing is, in itself, not bad. Whether or not shearing is appropriate depends upon the style of the garden and the species of the shrub. Both criteria must be met for sheared material to "work."
Formal Landscapes
The style of the yard must be formal as in a topiary, rose, knot or Japanese style garden. A sheared plant can be used as a single formal element of contrast. For example, a straight, sheared hedge may serve as a backdrop for a border of perennials; or a walkway might be bordered by sheared globes as commonly seen on estate grounds. In England one is apt to find countryside cottages featuring large boxwood shrubs sheared into the shapes of hens. What fun! In a Japanese garden setting, massed plantings are sheared to imitate a vista of low rolling hills. The lower story of sheared material is contrasted with a pond and open, sparsely branched trees.
Species for Shearing
Whether or not shearing is appropriate also depends upon the species of the shrub. All good pruning enhances the natural growth pattern or habit of the plant material itself. Shearing is no exception. As mentioned before, the criteria for good shear material are small leaves spaced closely together and a plant tough enough to take the shears repeatedly. Ideally, the plant chosen for shearing should be capable of greening back up if it has to be reduced in size. This makes broadleaf evergreens somewhat more desirable than needled evergreens. Sheared evergreen (broadleaf or needled) shrubs and trees are preferred over deciduous material because they look nice all year 'round. The most ideal plants for shearing are boxwood, holly, yew, privet, pyracantha, box honeysuckle, followed by some santolinas and some finely needled evergreens such as junipers, thuja and hemlocks. Other plants such as forsythia and philadelphus are tough enough to withstand tight shearing but the leaves are too large and, therefore, are not as attractive when sheared. Barberry and spirea have small leaves but are not tough enough to take tight shearing. They will develop dead spots, "bird's nesting" and generally look "ratty." Species planted for their flowers, will lose their spring display.
Some shrubs, such as escallonia, abelia and osmanthus, are the object of debate among gardeners because they do have small leaves spaced closely together and they are tough enough to take shearing. Some gardeners don't like to see them sheared because the fine flower display is compromised by heavy shearing done at the wrong time of year. Evergreen azaleas are the perfect example of this. Many selective pruners feel that azaleas should be allowed to be themselves, but many Japanese gardeners, and others who like the tight look, do shear them. If done at the right time, the azalea can have wonderful flowers as well.
Don't Misuse Shearing
Aside from considerations of taste, there are other good reasons to avoid the use and misuse of shearing as a pruning technique:
1. It locks you into a high-maintenance routine;
2. It is difficult in the long run to control the size of your shrub;
3. It is a drain on the health of the plants;
4. It subverts the purpose of many shrubs, sometimes by eliminating their flowers, or, more unfortunately, sometimes destroying their branch patterns and texture.
Don't Shear to Control Size
Because shearing is non-selective heading, you will stimulate bushy regrowth. You create a twiggy outer shell on sheared plants. This layer of twigs shades out the interior, which then becomes leafless and full of dead leaves and dead wood. Meanwhile the outer shell becomes thicker and larger every year because, as it is sheared repeatedly, it must be cut a little farther out to retain its greenery. This dense, twiggy outer shell makes size reduction difficult because cutting back too far exposes that ugly dead zone inside the shrub. It is also physically difficult to cut through the thick twiggy mass. Although most plants will eventually green back up when they are pruned back into the dead zone, but as you now know, the needled evergreens, such as junipers, won't. Therefore, shearing is not a good way to control the size of a shrub. Selective pruning utilizing the thinning cut ensures that there will be a green twig or branch to cut back to and can therefore be employed to reduce a shrub's size while retaining its natural look.
Only Tough Plants Take Shearing
Shearing is also a drain on the health of plants. Selective pruners spend most of their time opening up the plant to let in more light and air and to reduce the build-up of dead wood and disease. Shearing plants creates the antithesis of a healthy environment, making shrubs more prone to insect attack, dead wood and dieback. It adds a general stress on plants because the rapid, profuse growth promoted by repeated heading depletes their energy and in their resulting weakness and tender growth makes them more susceptible to injury from freeze or drought. This is why care must be taken to pick plants which are tough enough to take repeated shearing. Even then, the shearing must commence when the plants are young to avoid the sudden stress of shearing after they have reached maturity. Even on plants that are appropriate to shear, the good gardener will take time to reach inside and clean out the build-up of dead wood and dead twigs.
Shearing is High Maintenance
Another problem with shearing is that it is a high- maintenance chore. The growth which results from the heading cuts grows rapidly straight up and looks rather wild. Heading cuts stimulate rapid regrowth, which soon destroys the tidy look that the first shearing created. Although shearing the plant may take little time, it gets undone very quickly and locks the practitioner into frequent reshearing.
When plants are selectively pruned, the new growth matches that which already exists in the plant and looks more natural. The growth from a selectively pruned plant continues at about the same rate. Therefore, a selectively pruned plant stays in control longer. Shearing is a labor-intensive form of pruning. I have even heard it compared to drug abuse--the first time through is very gratifying and very quick, but the unwary wielder of hedge shears will soon be locked into a high-maintenance habit. It will take more and more shearing to keep a plant looking its same tidy way until one day the hapless homeowner can't see out the window or open the door blocked by a giant ball or box. And eventually, the plant's health will begin to show signs of deterioration.
Other Drawbacks
Aside from maintenance and health considerations, the gardener must also consider the purpose of plants when deciding how to prune them. Shearing often defeats the purpose of shrubbery, usually by cutting off the flowers. But other characteristics are subverted as well. True genius in landscaping is obtained by balancing theme and contrast. One of the elements of contrast is texture (for example, the fine leaves of a boxwood, the fluffy look of bridal spirea, the bold, deep leaf of a viburnum). Shearing will eliminate contrast of texture. Everything begins to look the same.
Lastly, shearing does great violence to plants which have been chosen for their secondary characteristic of fine branch patterns. Such a plant is Star Magnolia, which is valued for its flowers, but is also valued for its beautiful branch patterns and fuzzy buds. Other trees and shrubs highly valued for their fine branch patterns are the double file viburnum, Harry Lauder's walking stick, Japanese maple and Eastern dogwood. Shearing ruins them.
So, if you have a sheared hedge and do rent a pair of power shears, restrain yourself from taking on the rest of the yard. Don't get carried away with shear madness.
SUMMARY
Don't shear shrubs.
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