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.

Saturday, March 17, 2012

Formal vs Informal

     The Gardens of Versailles are among the most beautiful in the world. They represent a pinnacle of formal style in gardening that developed in the Renaissance. Symmetrical and composed of perfectly straight lines and perfectly circular curves, gardens like this have a machine-like precision that shouts man's domination over nature.

     They also required an army of labor to build and maintain in a society in which most considered themselves lucky to have a vegetable patch and a pig pen. Formal gardens like these are above all aristocratic. Only the extremely wealthy could afford them. But they set the standard for everyone else. Those merely well-to-do did what they could to emulate this style on a smaller scale and simpler design based perhaps on the labor of one full-time gardener. Yet others made do with a gardener who came once a week. At least up until World War II many middle class families were able to afford some regular gardening help based on available and inexpensive labor.

     At this lowest level the formal garden became reduced to a well-maintained lawn, formally trimmed shrubs around the house and perhaps a formal hedge in front or along the drive. But the clean lines and man-made character remained. A walk down almost any block shows that this style is still very popular.

     By the end of the nineteenth century, however, a new style had developed -- one that was more natural and informal. In part this was an effort to escape the staggering labor costs of formal landscaping as the price of labor kept increasing. (Today's formal gardens are almost all maintained by public institutions.) But the informal trend was also a result of a growing appreciation for nature itself. Voices arose that advocated, not imposing man's will on nature, but using man's talents to help nature along.

   This trend has continued to grow, fueled by things like the growing interest in ecology and the environment. A "natural" landscape is one that has no straight lines and is asymmetrical. Grassy lawns are reduced, or even eliminated altogether. Paths wander. Shrubs and perennials escape their beds.

     Most of us are aware of some of this even if we don't pay much attention to it. What strikes me, however, is that many of those trying a more relaxed style are still pruning their shrubs the same way: they shear the plant like a sheep instead of working with it. But that subject, dear reader, we will discuss next time.

Saturday, March 10, 2012

When to Prune

     We are heading into the '60's in Chicago this week, so I am jumping ahead of myself for those impatient to DO SOMETHING. The quick answer to the question of when to prune is "now." I have been pruning since the last week in February -- behind your back.

     We are in what the gardening books call the "late dormant period." In our climate zone most of our plants simply hibernate during the winter and wait for better times. Their vascular systems are shut down. Therefore when they are cut they do not "bleed." This is one advantage of pruning in the dormant season. Another is that the absence of foliage makes it easier for you to see what you are doing. Pruning in late winter also lets you cut out any winter damage that may have occurred. 

     But the biggest advantage of pruning about now is that we are performing our surgery just before our patients throw a huge amount of stored energy into a growth spurt. By doing our cutting now we make sure that our plants recover quickly and we also make sure that all the new growth is directed where we want it, not into leaves and branches that we are going to cut off later.

    Simple, right? But now, just like in grammar school, we no sooner learn a rule than we are told there are "exceptions." Wonderful! These are not as terrifying as many think, however. Most of them have to do with flowering, so if you goof up the worst thing that will happen is that you will lose your blooms for one season.

     The books make a distinction between "new wood" and "old wood." Many plants produce new flower buds at the same time they are growing new stems and leaves. These are "new wood" plants that can be pruned now because they have not started to produce their buds.

     The exceptions are those plants that produce their buds on last year's growth. The buds lie dormant during the winter and won't open until later this spring.The most popular of these "old wood" are forsythia and lilacs. If you prune these plants now, you will cut off their flower buds from last year and the new buds will not flower until 2013. This is not the end of the world, but it is pretty annoying if you planted them for their flowers. These old wood plants should be pruned once immediately after their bloom has faded and then left alone.

     You can make a good guess about which type of plant you have based on bloom time. Spring bloomers tend to be flowering on "old wood." Summer and fall bloomers are more likely to be based on "new wood." Logical, right? The tricky ones are hydrangea and clematis. Different species are either "new" or "old" wood plants, and the very-popular 'Endless Summer' hydrangea blooms on both.

     The Internet has made sorting through this confusion much easier than it used to be. If you know your plant's name, you can type in something like "pruning Mock Orange" to find out if it is a new or old wood plant. But even if you don't know what you have, you will do all right if you remember these three things: 1) Stay away from forsythia and lilacs. 2) Suspect spring bloomers to be "old wood" plants. 3) Be cautious with hydrangea and clematis if you can't find out which they are. Go ahead and make some snips but don't bet the farm on this year's pruning. You can always prune more next spring.

     Remember that all these rules are not matters of life and death. They are simply strategies for maximizing the effects of your labor. Nature "prunes" all year long via animals, falling tree limbs, hails storms and more. You can not really do serious damage to your plants by pruning at the wrong time. You can do a lot more damage by pruning in the wrong way. More on that later.

Tuesday, March 6, 2012


     Volumes have been written on the art and science of pruning. Theories have been advanced, disputes have erupted and blood has flowed. My own soap box on the subject is rather large and I have even been accused of "pontificating." So this is my first effort at reform: I will attempt to keep my messages short (Well, most of the time.) and try to avoid impressing you with my Latin. Mainly I hope to make pruning a little less threatening and a good bit more fun. Next to design itself, pruning is the most enjoyable part of my job and I wish I could do a lot more of it.

     So why prune in the first place? Because you want to have a green elephant in your yard, obviously. Topiary is an extreme example of one of pruning's three main purposes: to control a plant's shape to make it more graceful and attractive in our eyes.

     Second, we prune to improve the health of the plant -- to trim away storm or winter damage, to control or contain insect or disease damage, improve air circulation, and make it easier for the plant to rejuvenate itself.

     And finally, we prune to control size. In residential landscapes plants, especially trees and shrubs become real architectural elements like the size and shape of your house or whether your garage is in front or back. Whether thought through or not, plants have assigned spots, sizes and shapes in your yard. Unfortunately, unlike your trusty tool shed, plants grow. Worse than that, they frequently do not grow the way we think they should.

     I am enthusiastic about reason number two for pruning -- plant health. This is not done nearly enough. I am not averse to reason one -- shaping -- in judicious amounts, but far too much time is wasted on it in America. But the annual battle to force plants to be smaller than they want to be is one of the great scandals of our horticulture.

     I better pause here before I slip into pontificating.

Saturday, March 3, 2012

     T.S.Eliot to the contrary, April is not the cruelest month. At least in the Chicago area it is March. March is the month in which our hopes are repeatedly dashed. We get a couple of warm days and the snow recedes. Then we get buried. Our bulbs pop up and then freeze. One year out of four our beautiful magnolia buds end up popsicles in a late March deep freeze. For gardeners March is one of those months in which it is best just to pull the covers over your head -- or visit those friends in L.A. who have an extra bedroom. Usually the best slogan for March is the same as that for ancient Hades: "Abandon All Hope All Ye Who Enter Here."

     This year, of course, things are more bizarre than usual. I think I heard that from December through February the AVERAGE daily temperature In the Chicago area has been 34 degrees, making this the warmest winter since 1934. This has given our poor plants an even better shot at sticking their necks way out. You can almost see the guillotine shimmering in the sunlight.

     On the other hand we have dodged a number of bullets. We have had two winter storm warnings in the last ten days with predictions of 6-7" of snow. Nothing happened.

     So despite knowing better, I am officially launching my gardening blog today. And what do I have to say?

     First, no matter how warm it gets outside, leave your soil alone. If you mess with it you will only compact it. Don't dig it and don't even walk on it more than you have to.

     Second, clean up your mess. I live near a high school, so I have a ton of miscellaneous trash that gets caught in my hedge: fast food wrappers and beer bottles, of course, but also homework assignments, articles of clothing that some Mom made a teenager wear and mysteriously disappeared before she got home, etc. You could write a book based on the garbage my hedge collects.

     The mess is more than trash, however. It is time to pick up tree limbs and branches that broke in winter storms. It is also time to cut down ornamental grasses and the perennial foliage that has to give way to new shoots this spring.

     Knowing that the kid's violin lessons start in 20 minutes and that there is only so much time you are willing to waste on me, I will stop for now. The good stuff is in the next post: PRUNING.