More Soil Amendments

     My apologies. I have been AWOL for some time now. At the end of April my father died after a long illness. As his oldest son and de facto guardian in recent years, it fell to me to organize his departure, and I was absent for almost 10 days. Many joined together to celebrate his life. Now it is time to return to ours.

     I left in the middle of talking about soil amendments and the importance of adding organic matter to the soil. Today I want to focus on PH. In addition to being heavy clay, our local soil is also naturally alkaline. For the prairie plants native to this area, this is no problem. For many others, however, including many ordinary vegetables, a less alkaline soil would be welcome.

     For many evergreens and for plants that like shade, alkaline soil is inhospitable. They are used to a shady spot in a forest rich in organic matter - especially the acidic droppings of pines and other trees.

     This means that we gardeners should skew our soil amendments toward the acid side. We want our vegetable gardens to have a neutral PH -- about 7.0. If we are planting hollies, rhododendron, or many hydrangea, we want our soil on the acid side of neutral. If you have evergreens or hydrangea whose leaves seem to be abnormally yellow, that is an indication of chlorosis -- an affliction caused by soil that is too alkaline.

     In the city our naturally alkaline soil is accentuated by things like tuck pointing that add yet more lime to the soil and thus increase the alkalinity.

     For those who have established beds, you should use whatever is available to increase the acidity of your soil. The simplest of these is to throw your coffee grounds into your plant beds. A simple crock in the kitchen can store up several days worth of coffee grounds until you have the energy to take them outside.

     For problem areas, or for new beds you should include, in addition to compost, lots of peat moss ( which is acidic) and a teaspoon of soil sulfur for each plant. The sulfur should be mixed into the area below the plant. You do not want to let the plant roots be burned by direct contact with the sulfur.

     The Beverly area in Chicago is particularly shady. For those of us who live there, these recommendations are especially relevent. If you are going to plant a new bed, you have a wonderful opportunity to provide an environment that your plants will love for years. If you already have established beds, bit by bit amendments will also help. Scatch in a bit of soil sulfur around your hollies or hydrangeas every spring. Use some peat moss a a mulch, and make use of your coffee grounds.

Compost

     I think I have huffed and puffed about pruning long enough for one season. Besides, it is now that time of year where I am too busy to think, let alone opine in public.


     We have now passed the average last frost date in our area, and that means all but the most tender stuff can be planted without a lot of worry. It is like playing the black at roulette now, without any of the anxiety involved with playing a number. So all of us with cabin fever want to get out there and start new life in the plant kingdom.


     Part of my job is to try to convince you to put off that exciting planting day and do boring stuff instead. Especially if you are planting an entire bed, this is a once in a lifetime opportunity to improve your soil without tearing up all your plant roots.


     The soil around Chicago, at least on the Illinois side, is some of the best anywhere, provided some construction crew has not destroyed it. But is has two features that make it less than perfect: it is a heavy clay and it tends to be alkaline. Native plants have no problem with this, but many other plants do, including vegetables.


     The first and central amendment that everyone can use is compost. It is almost impossible to put too much compost in your yard. In fact, if you ever have to fill a low spot, please do not ever add "topsoil." Most commercial topsoil has been sifted through a screen to remove rocks and twigs and to make it soft and crumbly. But it only takes a couple of rains and a few footsteps for it to turn into that same old clay we know and love. Instead, get a blend of topsoil and compost...and then add more compost on top. With all that organic matter, you should expect the soil to settle a bit over time, so spread it slightly higher than you want it to end up.


     Compost breaks down over time and adds nutrients to the planting zone, as well as providing a good environment for all sorts of beneficial organisms in the soil. With enough compost added, you will not have to use commercial fertilizer at all.


     Moreover, all those bits and pieces create little voids around them that allow air and water to penetrate the clay and improves drainage as well as allowing more nutrients to reach plant roots.


     I can pontificate on this subject as much as on pruning. But if the clients now waiting  for me  caught me spending too much time scribbling,  their patience would evaporate, and I would be in big trouble.

THINNING WHERE IT IS THICK

Now you can see that the pruning here is more elaborate than simply cutting stems off at the ground.

   
    To pick up where we left off, if you cut 1/4 of your stems to the ground each spring, four years from now you will end up with a shrub whose effective age is 4 years, rather than 40. If I could figure out a way to do that for people I would have my own full-time gardener and condos on at least three continents.


     For those of us with over-sized shrubs, however, more may be needed. In addition to cutting older stems to the ground, you need to down-size the stems you keep. For trees and single stem shrubs, that is your only route.


     Before I wax mystical on you, we can start with a few guidelines:


     First, decide how low you want the shrub to become and cut everything off that is higher than, say, six feet. Then trim off  the sides where they hang over the sidewalk or run into other plants. This is your "butcher's cut." Or, if you want to be more artsy, it is the first block cut of a sculptor -- who may see a masterpiece within, but the rest of us just see a rough cube of stone. The practical thing here is that you have removed enough to see how the plant has been growing and what you will need to do.


     Second, start second and third cuts. As a rough way to start, make your second cuts 6" lower than your block cut and your third cut 12" lower. You end up with a shrub that has one third of its branches at three different levels. And you have punctured that dense shell at the top that prevents sun from reaching lower leaves.


     Third, with your second cut I hope you will start noticing how your plant grows. It is time to start looking seriously at what you are doing. Many shrubs, for example, tend to send up 4-5 branchlets where they were cut before. Some shrubs, like burning bushes and many viburnums, have enlarged nodes from which these branchlets protrude. So alter the 6", 12" scheme to fit the node. Make one of your cuts a cut that cuts below these nodes. Instant thinning. It does not matter where it is the first, second, or third cut, as long as you get the size you want.


     Now for the more mystical part.The 0, 6,12 rule and the cut below the node rule are just a rough start. Part of what they do is get you close enough to your plant to begin to understand it. As you are snipping you should also be looking at how it has grown. To the extent you understand the growth, you can begin to intervene in a way that helps the plant do what it wants to do, rather than imposing your will on it.


     The key thing here is to look at how branches form and how buds grow. Your general rules need to be modified to cut, where possible, to an already existing branch. If that is not possible, go for a bud. But not any bud. Look for one that seem to be going in the direction you want  - not straight up, not straight down, not back to the center, but angled in the direction you hope it will go.


     If this all sounds a bit intimidating, I apologize. Gardening is supposed to be relaxing, right? So do the 1/4 thinning from the ground first and follow the 0,6,12 rule. That is enough for the first year. Next year you can look at the results and come up with a more sophisticated approach. And if you make a mistake, don't worry about it. Plants face far worse enemies than you and they will survive your errors. And eventually they will be glad you are around.


     One of my favorite clients told me that pruning is now one of her best therapies for purging the frustrations of a trying day. Soon you will be able to join her.




     Third

Thinning Shrubs vs. Shearing

Many experts advocate removing 1/3 of the stems. I will jump for joy if you remove 1/4.

     Those who have been using hedge clippers for a number of years may have noticed something: no matter what you do, your shrubs keep getting larger. And while the outer shell stays nice and green, there is less and less below and inside. This is a result of unrelieved shearing without thinning.


     When you cut off the end of a branch most plants will grow two or more new tips to replace the old one, and the leaves become more dense. Within limits this is a good thing -- especially in shady areas where plants tend to open up.


     But repeated shearings make the outer shell too dense. The leaves on the top and sides block sun and air from the interior and the branches there die back. The effect is even worse when you have pruned in the notorious "W" shape that I mentioned earlier. Now you have an overhang that cuts even more sun from the plant's lower limbs.


     Even in formal gardens regular shearing needs to supplemented with thinning to allow sun and air to get to the interior of the plant.


     And here we come to my Number One Pruning Rule for multi-stemmed shrubs. It is simple, it is easy, and almost no one does it. Every spring you should cut up to 25% of your stems to the ground. If this sounds too scary, cut down one or two this year. When you notice in July that you can't tell the difference, you will be bolder next spring.


     You should go after the largest, oldest stems first, then stems that are going in a direction you do not like or ones that cross through the plant and rub against other branches. By doing this you accomplish four things:


     1. You open up the plant to more air and sun.


     2. You improve the shape of the plant by getting rid of stray and crossing stems.


     3. You rejuvenate the plant as old weary stems are replaced by new ones.


     4. You help control the plant's size because the oldest stems are the tallest and thickest and the most difficult to trim at the top. 


     I'll talk about pruning the the upper parts of shrubs next time.


     

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.

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.

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.