Sunday, March 25, 2012

Shearing Plants Instead of Sheep


 



    Let's talk about one of my pet peeves: shearing shrubs. I own a gas powered hedge clipper because I have clients who like their gardens formal. Many people, however, clip their shrubs because they are getting too big and hedge clippers are the only tools they know that will cut them down to size.


     This problem begins because some nursery or landscaper sold you a shrub that looked nice when it was planted but was destined to become three times as large in ten years . Either you notice one morning that you can no longer see out your front windows or you have to wage a constant war to keep that bush under control. Sometimes both things happen.

     So the first point to be made is that you should find out what size your new shrub will be at maturity and buy accordingly. Most plants are sold as babies and will grow substantially over time. This means that your landscape will look a little puny for a couple of years. Relax. Gardening is supposed to be relaxing, right? If you are super impatient and have to have it all now, buy mature plants and pay 8-10 times the price. You will be happy and so will the nursery. If you would rather take a trip to Europe, buy your plants small and enjoy watching them grow. Once they are full sized you will have next to nothing to do in the way of pruning.

     For those who like a formal look, keep in mind that the best shape for a sheared bush is a broad, rounded "A." This shape helps prevent damage from heavy snow and storms. It also helps provide additional sun to lower reaches of the plant. Keep in mind also that while yews, boxwoods, and privets tolerate repeat shearings, other shrubs are less forgiving. The more you cut them the uglier they get.

This "good" shape is not good enough. the top corners should be rounded as well.
     Most importantly, shearing by itself is not enough to keep your shrubs healthy and shapely. I am sure some of you have noticed that despite 4-5 prunings a season, your plants keep getting larger. Moreover, while the top stays dense, the plant starts to empty out down below. And it wants to turn into a "W" instead of a broad, rounded "A." You have all seen those shrubs that look like overgrown mushrooms, or the yews whose tops block the windows but whose legs are embarrassingly naked.

     Shearing encourages branching at the cut, so your shrub becomes more and more dense in the outer shell of the plant. Eventually the new growth blocks lower branches from the sun --and sometimes from sufficient air as well.. The interior begins to die out and the new growth that appears lower down grows away from the center of the plant in an effort to reach some sun. Your "A" is on its way to becoming a "W."

     You need to supplement your shearing with thinning. We'll talk about that next time.

3 comments:

  1. It doesn't help that nurseries often out and out lie about the ultimate size of a given shrub or provide misleading information. I have a "dwarf" crepe myrtle that now tops 12 feet tall as an example. So it is not surprising that the perfect little bush for that gap ends up the 800 pound gorilla of the landscape infringing on the air rights of the surrounding perennials.

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  2. You are right, of course. My favorite example is the burning bush Euonymus alatus 'Compacta." For years nurseries have sold this a a dwarf variety. In fact, the "compacta" refers to the size of the wings running along the stem, not the size of the plant, which can easily reach 10'x10'.

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  3. Thanks for the sharing Excellent information.........Plants Toowoomba

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