Tree pruning is the process of trimming tree branches to help them grow more evenly. It can also be used as a way to control growth and remove dead, diseased or broken limbs. Pruning can also give trees that are too tall for their surroundings an opportunity to spread out their crowns and reduce competition with other plants growing around them.
Good trunk structure is essential because this will determine how well your tree grows over time, including its health, shape and size. Tree pruning should not be done just because you want a certain look but rather when the tree needs it to keep healthy and have good growth potential. Doing so may prolong its life expectancy, and make sure it continues to provide shade in your yard for years on end!
Pruning a tree can have many benefits. The first and most important is keeping the people around it safe. A dead branch can fall from a tree at any time, endangering nearby people, buildings, and power lines. Therefore, removing dangerous limbs and maintaining a safe tree is always the best course of action.
However, depending on the size of the tree and the location of the branches to be pruned, pruning itself can also be very dangerous. Therefore, to ensure your own personal safety, we recommend you let an expert do any pruning you’re not absolutely comfortable and confident in doing.
Tree growth and structure
There are many reasons why pruning a tree is important. First, pruning a tree can influence in what way the tree grows. With proper pruning, a tree can be made to grow into a certain configuration of limbs and branches that is more ideal for the tree’s structural integrity.
Maintaining the tree’s structure helps to mitigate the risk of broken limbs and falling branches. A properly pruned tree will not compromise branch structures and improper weight distribution that could lead to disaster later in the tree’s life.
Structural pruning can also greatly improve the general look of the tree. If aesthetics are important to you, proper pruning can make a tree grow in the desired fashion.
When to Prune
Remember, it’s important that any pruning (other than emergency branch removal) be done in late fall or winter, during the dormant season. It’s during this time that the tree is least susceptible to harm that may result from pruning.
Trees are susceptible to stress just like any other creature, and removing their branches does cause damage to the tree. When the tree is dormant, however, less sap is lost and, since they are dormant as well, insects and fungus are less likely to damage the tree further. In addition, certain species of trees require more precise timing and different approaches for proper pruning. If you’re ever in doubt, contact a certified arborist instead of risking both the tree’s safety and your own.
Less is More
It’s also important to remember not to prune too much off of a tree. Generally, you want to prune the smallest amount you possibly can that achieves the desired effect.
Never prune more than ¼ of the crown of a tree, as this is where most of its leaves are located and consequently where it gets most of its energy. You run the risk of fatally damaging the tree if too much is pruned too quickly. Again, a certified arborist is your best bet if you want the job done properly and safely the first time.
Damage From Over Pruning: Can You Kill A Plant From Over Pruning?
When you move into a new place, especially one with a large, mature landscape, the gardener in you will immediately start twitching if the plants on your lawn are overgrown. As a result, you may develop an irresistible urge to open the canopies and hard prune every plant you can reach — and some that belong to your neighbours.
But, over-pruning in plants can be as bad, or even worse, than not pruning them at all. Can You Kill a Plant From Over Pruning? Although over pruned trees and shrubs don’t usually die if some part of the canopy remains, the damage from over-pruning can be extensive. Over pruning reduces the foliage that’s available for making food for the rest of the plant and can allow pests and diseases access to the tree if cuts are made incorrectly.
In addition, plants may sprout excessively in response to so much canopy loss to protect the plant’s bark from sunscald and increase food production. Over time, continued over-pruning may lead to branches that are too weak to tolerate wind or ice loads, or the plant may simply exhaust itself trying to replenish its canopy.
As a result, the plant may become extremely weak, allowing various pathogens and insects to invade. So, although pruning may not kill your plant directly, over pruned trees and shrubs can die as a long term result of the associated stress.
How to Repair Over Pruning
Unfortunately, the damage from over-pruning can’t be fixed, but you can help your tree overcome the many difficult days ahead. Provide proper fertilisation and water to help your plant along; its diminished capacity for photosynthesis means that it’s more important than ever that your plant has all the building blocks it needs readily available for food production.
Wound dressing is rarely recommended, with only a few exceptions, such as when oak wilt disease is common in the area. In this case, the wound dressing can prevent the penetration of vectoring beetles into healing tissues. Otherwise, leave wounds open. It is now believed that dressing wounds slows the natural healing process in bushes and trees.
Time is the only real cure for over-pruning, so do so carefully when you decide to prune. Remove no more than one-third of the canopy at a time, and resist the urge to top your trees. Topping is a practice that’s very bad for plants and may lead to brittle canopies.
The Wrong Time To Trim Trees
Rich in Fairfax Station writes, “I help a neighbour lady who has a large River Birch that’s very close to her front door. She wants to remove some branches that are beginning to have an impact on her access. They are not small branches. When is a good time to remove them, and how should we seal the cuts to prevent the disease from entering the tree?”
You are very wise to ask before cutting, Rich — from now through the beginning of winter is the worst possible time to remove healthy branches from a tree, especially one as magnificent as a river birch!
Pruning during the growing season always stimulates new growth. However, during summer’s heat, producing that ill-timed new flush of growth greatly stresses a tree. Pruning in the fall is even worse as it prevents the tree from going into a natural dormancy.
The exception is heavily damaged, disease or dead wood. Those beat-up branches can — and should — be removed at any time. But the removal of healthy limbs should only be done in the middle of winter — the dormant period when the tree is essentially asleep — or in the spring when the tree has just begun actively growing again and new growth is forming naturally.
If you try to remove a 100-pound branch all in one piece, it will swing around, smack you upside the head and break your shoelaces. It will also tear the bark directly below that branch section all the way to the ground. That’s why large branches should always be removed in manageable sections — a foot or so at a time.
When you are ready to make the final cut closest to the tree, locate the branch collar — the round structure were the branch meets the tree. You want to leave that collar on the tree when you remove the last of the bran. But, again, don’t cut flush to the trunk. Nothing should be used to seal the cuts. Nature knows how to do that much better than we do.
Mushrooms on wood mulch
All of a sudden, we are having a huge problem with mushrooms around our shrubs, hostas, lilies and other plantings. The area is hardwood-mulched every year. Yes, we know that you say it’s bad, but we’ve done it for 15 years, and this is the first time we have had a mushroom invasion. Is there anything we can apply to eliminate them? The scene out there is horrible!”
So, let’s see, you knew it was bad to use wood mulch, you kept using wood mulch anyway, something bad finally happened, and now you’re surprised? The truth is that everyone who falls for wood mulch marketing will eventually get hit with a flush of mushrooms and/or other nuisance molds — some of which can cause severe (and expensive) cosmetic damage to homes and cars. Some people get hit with such problems the very first year they spread wood mulch, others get away with it for a decade or more. But sooner or later, the chickens — eh — fungal spores — will come home to roost.
For now, you can try spreading coffee grounds, lime or wood ash around the ‘shrooms to stop the spawning. But don’t yank them out. That spreads the spores.
Coffee grounds supply nitrogen, while lime and wood ash make the mulch more alkaline — both of which help inhibit fungal growth. But don’t use both — choose either grounds or wood ash/lime.
And of course, the long term answer is to switch to a mulch that isn’t attractive to rogue fungus such as compost, pine straw or pine fines.
Wood mulch = worms
Dwight in Randallstown writes, “I recently changed my mulch to wood, and now bugs have appeared; what are they and what should I do?”
The images Dwight sent show a severe infestation of bagworms on an evergreen. These clever caterpillars (every pest with the word “worm” in its common name is actually a caterpillar of some kind) live in small nests — or “bags” — that look a lot like the pine cones that naturally appear on the plants they attack. And so the “worms” often escape detection — sometimes even while they’re eating the evergreen to the ground.
Bagworms — and similar pests such as tent caterpillars and fall webworms — often appear in response to stress, such as feeding with chemical fertilisers or — ahem — mulching with chipped-up pallets from China spray painted some God-awful colour.
The initial answer to any caterpillar problem is to spray Bt on the plant. Sold under brand names such as Dipel, Thuracide and Green Step, this organic pesticide made from naturally occurring soil bacteria only affects caterpillars that eat the sprayed parts of the plant. Bt harms nothing else. The “worms” will stop eating immediately and die shortly afterwards.
In the long term, avoid using chemically-based plant foods and stop using mulches that stress your plants. Instead, switch to compost or pine straw. A healthy, happy plant rarely suffers these kinds of attacks.
Five Shrub and Tree Pruning Mistakes and How to Avoid Them
Ask any tree service professional what they are asked about most, and they’ll tell you it has to do with pruning, the periodic cutting back of perennial woody shrubs and trees.
Many homeowners understand why these plants need to be pruned periodically. They’ve no doubt heard at one time or another that properly pruned plants are generally healthier, live longer, and look better.
While there are many benefits of properly pruned trees and shrubs, most people have no idea what ‘properly pruned’ actually means. The truth is, pruning is both an art and a science; it requires the pruner to get up close and personal with the plant while also taking a few steps back to see how each cut has impacted the overall look of the plant and the landscape.
What makes matters worse is that there is no overarching rule to follow. Different types of plants, trees, and shrubs require different pruning techniques. The bottom line: know your plants, or hire someone who does.
Here are a few examples of how DIY pruning can go wrong and what you can do to avoid these all-too-common blunders.
Mistake #1 – Pruning at the wrong time of year
Although there are a few instances when pruning can (and should) be done at any time (for example, when removing dead, damaged, or overlapping branches), most plants benefit from pruning at specific times of the year.
Prune plants that flower during the summer, such as Rose of Sharon, barberry, and gardenia, while they are still dormant in late winter or early spring. Without foliage, the woody structure of the plant is more visible, making it easier to determine where cuts should be made.
The rush of spring-induced growth will also allow the plant to heal itself faster. Arborvitae, cedar, hemlock, and juniper trees should also be pruned during this time.
Prune woody shrubs that flower during the spring, such as azalea, lilac, forsythia, and rhododendron, immediately after their blossoms fade in late spring/early summer. Doing so will increase the plants bloom in the following year. Trees such as cherry, ornamental pear, pine, and spruce should also be pruned back in early summer.
Most importantly, tree service professionals recommend that homeowners avoid pruning back trees that produce a heavy sap flow during the spring until after the leaves have fully developed.
Otherwise, the cuts may put too much stress on the plant and make it make it more susceptible to pests, disease, or drought conditions. This includes many of the most abundant New England tree species, such as birch, elm, and maple.
Mistake #2 – Bad placement of the cut(s)
Pruning back small- to medium-sized trees and shrubs isn’t necessarily a difficult task. However, it does require some forethought and attention to detail. Ironically, the best pruning jobs are least likely to be noticed – at least to the untrained eye.
It’s advisable to avoid pruning a young, newly planted tree for at least the first few growing seasons. These young trees need as many leaves as possible to capture sunlight and create enough stored energy to withstand dormancy.
Another good practice is always to prune back to a healthy limb or stem to avoid leaving a stubbed end. Remove branches that cross or rub against each other as well as those that hang down low to the ground.
Other ‘must go’ candidates include any dead or diseased limbs, suckers growing from the base of the tree, and branches that grow parallel or too close to the trunk. Additionally, to encourage upward growth of the tree’s crown, remove the branches below and periodically remove new growth forming from the cut as it occurs.
Most professional tree care services recommend pruning back a tree by no more than ¼ of its total size in a single year.
Mistake #3 – Using the wrong tool for the job
The key to making a good, clean-cut when pruning is using clean, sharp, and right-sized tools. Homeowners should begin each season by making a careful inspection of their pruning saw blades, loppers, and shears.
Blades should be sharpened and free of rust and debris so as not to infect the tree with a disease from another plant. As a rule, loppers are best used to remove difficult to reach limbs that are no wider than 1”.
Being able to use two hands to cut with loppers gives the pruner twice the cutting power with half the effort. However, for branches greater than 1”, tree service pros suggest that This is because these pruning saw is a much safer choice.
Branches should be cut as close as possible to the ‘collar’ where the limb meets the main stem or trunk. Be sure to avoid tearing or stripping any additional bark below the cut. Follow the 3-Cut Method of removal for large limbs by making a preliminary undercut about 12”-15” from the ideal pruning location, followed by a secondary cut to remove the branch from the trunk. Lastly, make a final cut at the union to remove the stub. A good pruning cut will heal quickly and naturally.
Mistake #4 – Choosing not to prune
Don’t be fooled. There is no such thing as a maintenance-free landscape. Even here in Maine, with our super short growing season, the reality is that every plant on your property will grow and continue to do so season after season.
Rather than falsely believing that cutting back trees and shrubs is somehow ‘hurting’ the plant, Mainers should instead keep the notion that Nick Lowe first penned in his 80’s pop hit, “You’ve gotta be cruel to be kind, in the right measure…”. Strategically pruning back small trees and shrubs will actually produce healthier, longer-lasting, and more vibrant plants for many years to come.
Mistake #5 – Biting off more than you can chew
While there are many pruning tasks that homeowners can often handle on their own, there are times when the job should be handled by a trained professional. This includes removing limbs that overhang structures such as a house, shed, or fence as well as anything near – or potentially near – electric power lines.
Not only do tree service professionals have the specialised tools and equipment to get the job done faster and cleaner. They also have many years of tree pruning experience to help them better anticipate what could go wrong and modify the work plan accordingly it doesn’t.