Pruning Large, Overgrown Shrubs
Shrubs are valuable assets to a home landscape. Shrubs are often planted for their ornamental characteristics, such as flowers, colorful fall foliage, or attractive fruit. They also can provide privacy, block views, and attract wildlife. For shrubs to perform well in the landscape, home gardeners must prune them properly. Proper pruning helps to maintain plant health, control or shape plant growth, and stimulate flower production.
Many deciduous shrubs (those that lose their leaves in the fall) can be kept healthy and vigorous by removing a few of the largest, oldest stems every 2 or 3 years. Unfortunately, many individuals fail to prune their shrubs because of a lack of time, knowledge, or courage. As a result of this neglect, shrubs often become leggy and unattractive. Flowering shrubs that are not pruned properly may not bloom well.
Proper pruning can renew or rejuvenate overgrown, deciduous shrubs. One method is to prune them back over a 3-year period. Begin by removing one-third of the large, old stems at ground level in late winter/early spring (March or early April). The following year (again in March or early April), prune out one-half of the remaining old stems. Also, thin out some of the new growth. Retain several well-spaced, vigorous shoots and remove all of the others. Finally, remove all of the remaining old wood in late winter/early spring of the third year. Additional thinning of new shoots also should be done.
A second way to prune overgrown, deciduous shrubs is to cut them back to within 4 to 6 inches of the ground in March or early April. This severe pruning will induce a large number of shoots to develop during the growing season. In late winter of the following year, select and retain several strong, healthy shoots and remove all others at ground level. Head (cut) back the retained shoots to encourage branching. Large, overgrown lilacs, honeysuckles, dogwoods, spireas, and forsythias may be pruned in this manner. Lilacs rejuvenated by this method will not bloom for 3 to 5 years.
Deciduous, formal hedges (those pruned to a definite size and shape), such as privets, that become open and leggy also can be rejuvenated by pruning them back to within 4 to 6 inches of the ground in late winter/early spring. To obtain a full, thick hedge, prune (shear) the shoots often as they grow back in spring and summer. Also, make sure the base of the hedge is slightly wider than the top to encourage growth close to the ground.
Large, overgrown evergreen shrubs, such as junipers, are a more difficult problem. Junipers possess bare or dead zones in their centers. They can not be pruned back severely because they are incapable of initiating new growth from bare branches. Large, overgrown junipers that have become too large or unattractive will need to be removed and new shrubs planted.
Although many overgrown, deciduous shrubs can be renewed or rejuvenated, it’s much easier to prune them on a regular basis. Regular pruning will keep the shrubs full, healthy, and attractive.
This article originally appeared in the March 7, 2003 issue, pp. 20-21.
How to cut back an overgrown hedge
A HEDGE is great, as a boundary or as a backdrop for shrubs and flowers, and a hedge is an attractive garden feature on its own account, but what happens when hedges get too big, as they almost invariably do? Hedges almost always eventually grow too tall and too wide. This can happen as a result of neglected clipping, but it also happens with properly clipped hedges because a small amount of new growth is left each growing season.
If just one centimetre is left each year, after 10 years the hedge can be 20 centimetres wider and 10 centimetres taller, and many hedges have much more than one centimetre of growth left in place. But action can be taken. The top part of the hedge can be cut off, taking as much as is desired away, or even cutting the hedge down to near ground level. An established hedge quickly re-establishes when cut back hard, but it is really a waste of its height and it takes extra time to re-grow, so hedges are usually only cut back part-way. The sides can be cut back too – a process known as “splitting” a hedge.
The idea is to take off one side of the hedge this spring and the other side next spring or in two years time. If you want to take a small risk, both sides can be done at the same time.
Some hedges cannot be cut down hard or split. For example, all kinds of cypress hedges, including leyland, cannot be pruned back beyond the green foliage because they will not re-sprout from brown stems. Although thuya and yew are both coniferous types like the cypresses, these two respond well to hard pruning and can be cut back.
Hedges that are suitable for topping and splitting include deciduous and broad-leaved evergreens, such as hawthorn, beech, holly, olearia, lonicera, laurel, privet, escallonia and griselinia. When splitting a hedge, the outer layer of growth on one side is cut away – back into the older stems but short of the trunk. The best tool to use is a long-handled shears; these are available in any garden outlet and worth having for this job and for any heavy pruning.
It may be necessary to use a pruning saw, or bow saw, on the more substantial branches. Keep the new face of the hedge as straight as possible when cutting back hard. Feed the hedge with some tree and shrub fertiliser on either side and water it well if there is a prolonged dry spell.
Take the opportunity to clear out the base of the hedge, getting rid of ivy or other weeds and clearing out debris. Clip the new growth to shape as it appears. If the re-growth is satisfactory, the other side can be cut back next year. Splitting can be done as growth begins, which is soon if not right away.
Cutting Back Privet: How And When To Prune Privet Hedges
Privet hedges are a popular and attractive way of delineating a property line. But if you plant a hedge, you’ll find that privet hedge pruning is a must. If you are wondering when to prune privet hedges or how to prune a privet hedge, read on. We’ll provide tips on cutting back privet.
Pruning Privet Hedges
Privet (Ligustrum spp.) is an excellent shrub for hedges. It has oval or lance-shaped leaves and grows dense, compact foliage. Privet is an evergreen bush in U.S. Department of Agriculture plant hardiness zones 8 through 10.
Privet works well for tall privacy screens. It is one of those shrubs that make good hedges 5 feet (1.5 m.) tall or taller. But privet gets leggy and uneven over time. In order to keep these hedges looking neat and attractive, you’ll definitely need to start privet hedge pruning.
When to Prune Privet
You’ll want to undertake these pruning steps in late winter. That is, removing damaged branches or opening the interior of the shrub should be done before spring growth begins.
When to prune privet by trimming the outside of the hedge? This type of privet hedge pruning should take place in mid-spring after the annual growth has begun.
How to Prune a Privet Hedge
Privet hedge pruning involves cutting back privet shrubs. Pruning privet hedges requires some effort, but it is worth the time and energy. You’ll need to wear gloves since privet sap causes irritation and rashes.
So how to prune a privet hedge? The first step in privet hedge pruning is to trim out crossing branches. You’ll also want to keep cutting back privet to remove damaged or dead branches. Remove them at their base with loppers.
Once you finish this, remove several large branches from the inside of each shrub to open up the center of the hedge. Use bypass pruners for this, cutting back each branch to a side branch.
In time, you’ll want to trim and shape the outside of the privet hedge. You first want to determine how high you want your hedge. Then get several stakes of that height and plant them in the ground toward the center of the hedge. Tie a string between the stakes.
Shear the top of the privet along the string line, then shear the face of the hedge down to the bottom in a diagonal downward slope. The hedge should be narrower at the top than the base on each side in order to allow light to touch the entire hedge face.
To rejuvenate a privet hedge, cut the entire hedge back to within 12 inches (30 cm.) of the ground. Do this in late winter. The shrubs resprout after being cut back hard.
Five Awful Plants for the Front of Your House
In the garden, a little knowledge can be very dangerous indeed. I vividly remember the day our neighbor complained that his vegetable plants mysteriously started shriveling soon after he sprayed them for bugs. I asked when he’d used that spayer before. “Oh, it was about a week ago,” he replied. “I sprayed the grass for weeds.
Well it didn’t take Isaac Newton to surmise what had happened. Our neighbor neglected to clean out his sprayer. Now the same chemical he had used to hammer his dandelions was stir-frying tomatoes.
All of which goes to show that when it comes to dealing with bugs, weeds, fungi, and critters, it’s not enough to get most things right. You have to get them all right.
Each part of a well-designed landscape has its own function. The front yard reflects how you present yourself to friends, neighbors, and passerby. It should clearly guide guests to the entry. It should also anchor the house so it blends well with the natural landscape. The backyard–whether it contains a child’s play area, a lush perennial border, a treasured collection of plants, beautiful garden accessories, or simply a comfortable sitting area–should be your private space. All houses need practical service areas where you can conceal items such as trash receptacles, potting benches, and tools. . Here, we will focus on the front yard. Not just this space but the plants that we suggest you never ever plant for reasons that Grumpy will tell you about.
Sometimes in order to get people to do something good, you have to make them understand what’s bad. With that thought in mind, I’ve selected five of the worst things you can plant in front of your house. Some are ugly; some are monstrous; some get bugs and disease; and some manage to do all of these things.
Undoubtedly, some of you have these plants in front of your house and will shortly be greatly offended. That’s OK. Feel free to make disparaging remarks about my worthless, parasitic cat. He won’t know. He can’t read (though he does watch TV). Kinda like Rick Sanchez on CNN.
Awfulest of the Awful — Golden Euonymus
If you plant this in front of your house, you probably gave your girlfriend a pop-top for an engagement ring. I used to call golden euonymus a “gas station plant,” until gas stations cleaned up their act and substituted plastic palms. Plants like this do nothing for the housing market. They are a sign that says, “For Sale by People with Absolutely No Taste.”
So what’s wrong with golden euonymus (Euonymus japonicus‘ Aureomarginatus’)? Let me count the ways:
1. Mildew and scale eat it up.
2. The foliage often reverts to green, so you wind up with a bush that’s half green and half yellow.
3. The garish foliage is about as subtle as a working girl’s wardrobe.
4. Out-to-lunch people pair it with ‘Rosy Glow’ barberry, a look much favored by legendary garden designer Ernest T. Bass.
Awful Plant #2 — Bradford Pear
Every Grumpian should have seen this one coming. I hate Bradford pear (Pyrus calleryana ‘Bradford’)! It’s everywhere. Bragging about having one in your front yard is like bragging you have a toilet in your house. Bradford Pear is fast growing, easy to transplant, easy to grow, with showy spring flowers and spectacular red fall foliage. These attributes have led it to become one of the South’s most overplanted trees. Lacks a central leader; main branches emerge from a common point on trunk, often causing tree to split in storms. Bradford pear grows much bigger than people usually envision: in 20 years, it can reach 50 feet high, 40 feet wide. Newer pears, such as ‘Chanticleer’ and ‘Trinity’, are better choices for most gardens.
This is why I despise it:
1. It gets too big for the average yard — 50 feet high and 40 feet wide. The only excuse for planting a row of them is if you’re trying to block the view of a highway overpass.
2. Surface roots and dense shade makes it impossible to grow grass beneath it. Of course, if you’ve already blacktopped your yard, this won’t be a problem.
3. Weak branching structure makes it very prone to storm damage. Photograph it when it’s pretty. It won’t stay that way long.
4. Its spring flowers smell like fish.
5. Although its flowers are self-sterile, they can cross-pollinate with other selections of callery pear, such as ‘Aristocrat’ and ‘Cleveland Select.’ When they do, they produce thousands of tiny pears, which give rise to thousands of thorny seedlings are are now invading the countryside.
Awful Plant #3 — Redtip Photinia
Now I know what a lot of you are saying. “How can he hate such a purty plant? I love those shiny red leaves and the white flowers. What a churlish Grump!”
The popularity of Fraser photinia just goes to show that nothing succeeds like being obvious. A chance seedling discovered around 1940 at Fraser Nursery in Birmingham, Alabama, Fraser photinia (or redtip, as it is also known) displayed new leaves of bright red rather than the usual green. People flocked to buy it. Today, more homes probably have Fraser photinias than indoor plumbing.
Here’s my beef with Fraser photinia (Photinia x fraseri):
1. Like Bradford pear, it’s planted everywhere in the South. Find me a trailer park, parking lot, or chain-link fence without one. It’s about as common as clipping your toenails during the sermon.
2. It grows fast and big — up to 15 feet tall and wide, much too big for the front of your house, unless you’re hiding from the law. So you have to shear it often, which brings us to problem #3.
3. Most people grow it for the bright red new leaves that gradually turn green. The more you prune, the more red leaves you get. Trouble is, the new growth is extremely susceptible to a disfiguring disease, called Entomosporium leaf spot. Small spots appear on young leaves. As the spots age, the centers turn grayish with a dark purple border. Severely infected leaves drop prematurely.
The solution? The fungus that causes this leaf spot only attacks new, red growth. Mature green leaves are immune. Splashing water and wind spread the disease from leaf to leaf. To prevent it, remove and destroy infected leaves. Do not wet leaves when watering. Avoid summer pruning, which results in a flush of susceptible new leaves. Spray the plant with chlorothalonil (Daconil) every 10 to 14 days from bud break in spring until all new foliage has matured.
Unless you spray regularly with a fungicide, the disease eventually kills the plant — which, come to think of it, isn’t so bad.
Awful Plant #4 — Leyland Cypress
Very few people who plant this monster have any idea how big it gets — more than 70 feet tall and up to 15 feet wide. And because it can easily grow 3 feet a year, it doesn’t take long to resemble a Saturn 5 rocket. Still, people love planting this thing on the corner of the house. The only house big enough for this is Biltmore. In recent years, Leyland cypress (x Cupressus leylandii) has come under widespread attack by a potentially fatal fungus, seridium canker, which often causes trees to gradually die from the top down. Drought stress favors development of this disease. Leyland cypress has become the South’s number one choice for tall screens. Once established, it can easily grow three to four feet a year. Just remember, though, that it eventually grows 60 to 70 feet tall if unpruned.
Problem one with Leyland Cypress is called Seridium canker. Older interior foliage yellows, them browns. Twigs and branches die. Sunken reddish, dark brown, or purplish cankers form on the bark and ooze sap. Infection usually affects the lower branches first, then travels up the tree.
There is no chemical control for this disease. Avoid wounding the bark. Any type of wound provides an entry point for the seridium fungus. Prune out diseased branches, cutting 6 inches below the site of infection. Space plants adequately so that air can freely circulate among them.
Problem two with Leyland Cypress is needle or tip blight. During warm, wet weather the needles closest to the inside of the tree turn tan or gray, then die, leaving the inside of the plant bare while the outside remains green. Or needles on the tips of branches turn brown and die, and tiny black dots appear on dead needles and stems.
These problems usually affect plants growing too close together. The dense foliage restricts air circulation, so foliage doesn’t dry quickly. This makes things easy for either of two pathogens – Cercosphora, which also causes needle blight on Japanese cryptomeria and related species; and Phomopsis, which also causes twig blight of juniper. To control these problems, space Leylands eight to ten feet apart. Avoid wetting the foliage.
Awful Plant # 5 — Privet
I know a guy named Dr. Dirt who calls these shrubs “privy plants.” He doesn’t know how right he is. I’ll admit that some of the broadleaf species, such as waxleaf privet (Ligustrum lucidum) and Japanese privet (L. japonicum) have some use in the landscape as limbed-up trees, but the small-leaf hedging types, such as California privet(L. ovalifolium) and Chinese privet (L. sinense) are absolute garbage that belong in a privy. Provet is a fast-growing plant often used in screens and hedges. Some species are invasive. Many people refer to privet by its botanical name, Ligustrum. A more accurate name is “Disgustum.” How come?
1. In spring, privet produces white flowers, whose sickeningly sweet odor reminds me of the deadly dikironium cloud creature on “Star Trek.” To be fair, the cloud killed people by robbing their blood of iron. Privet flowers just cause allergies.
2. The flowers give rise to hundreds of blue-black berries relished by birds, who spread them all over the universe. As a result, privets are incredibly invasive and weedy. Plus, they grow really fast and need trimming about every two minutes or they’ll swallow your house and dog.
Now here’s the weird thing. Of all the variegated plants in the world, I think variegated Chinese privet (show above) is one of the better-looking. In fact, it’s perfect for next to your privy. But if I could snap my fingers and make all the privet in the world disappear, I would. I’d do the same for spammers.
A problem with privet are scales. White, yellowish, gray, reddish, or brown bumps encrust stems and undersides of leaves. Leaves yellow, brown, and then drop. Stems die back. These bumps are scales–sap-sucking insects that weaken the plant. Spray with horticultural oil, making sure to coat all leaf and stem surfaces. Or apply a systemic insecticide, such as acephate (Orthene).
Another problem is leaf spot. Irregularly shaped tan spots surrounded by dark brown border appear on leaf margins and at the tip. The spots become sunken with age. Caused by a fungus, leaf spot is unattractive but not life-threatening to the plant. Selectively prune (thin) dense hedges to improve air circulation through the plants. Avoid overhead sprinkling. Water plants early in the day to allow them to dry completely before evening. If practical, pick off and destroyed spotted leaves. On plants previously affected, spray new healthy leaves in spring with a Bordeaux mixture, chlorothalonil (Daconil), or maneb.
You can’t blame everything that goes wrong in your garden on a bug, blight, or critter. Some things may be your fault. Seven other things to keep in mind:
1. Crowding plants. Jamming plants together may give your garden a mature look intitially, but it reduces air circulation around leaves and stems, promoting disease. And it weakens plants by forcing them to compete for sunlight, water, and nutrients.
2. Improper watering. If you really want to kill a plant, giving it too much or too little water is a great way to do it.
3. Nicking the bark. Barks works like your skin: It keeps good things in and bad things out. Accidentally wounding the bark of a shrub or tree with a string trimmer, lawn mower, saw, or hockey stick promotes ready access for insects, fungi, bacteria, and viruses.
4. Monoculture. This term means planting large numbers of the same plant close together. All of the plants have the same susceptibility to certain pests. So if those pests show up, instead of one or two plants dying, all do.
5. Overfeeding. Giving a plant too much food, particularly nitrogen, encourages lush, soft growth that insects and diseases relish.
6. Topping trees. Read our lips. Topping trees is always a bad idea. It not only ruins their appearance, but also makes them prone to insect and fungi attack, as well as storm damage.
7. Scalping the lawn. So think cutting the grass down to the soil line means you won’t have to mow it often? Well, you’re right, because doing so repeatedly weakens the grass so much it might die. Unfortunately, the weeds that soon replace it like close cutting. So you’ll end up mowing those instead