When to prune maples?

When to prune maple trees – its different from most tree species.

Not all trees are the same when it comes to pruning. While most species of trees are pruned in winter to early spring, some are pruned at other times such as the maple tree.

When is the best time to prune maple trees? Mid-summer, no later than early fall so that the cut has time to heal or harden off before winter hits. Maple, Birch and Walnut trees all fall into this category that tend to ooze sap when pruned.

If needed you can lightly prune maple trees at other times of the year under different situations and circumstances. Read on to learn about them.


Best Time To Trim Maple Trees

While most trees are supposed to be pruned earlier in the year, that is when the maple tree is pumping sap. Most have heard of Maple Syrup. From late winter to early spring is when maple trees are tapped to collect the maple sap which is then boiled down into syrup.

To avoid excessive oozing of sap, maples should be pruned in the mid-summer time frame. This is when sap production is greatly reduced and it will give the trees time to harden off or heal the cut before winter comes along.

For a visual, observe when the leaves are fully developed. This is when the sap stops running and it is better to prune.

Mature maple trees can withstand light pruning during the peek sap season. It may look like you are hurting the tree with all the sap running out of the tree, but a mature tree can handle this.

If you are working with maple saplings it is another story. Avoid pruning them during peak sap season if at all possible. Their support networks are not completely developed yet and the tree will suffer greatly.

A secondary time frame when you can think about pruning maples is when the tree is fully dormant during the dead of winter just before the sap starts pumping up through the tree.

When Should You Prune Red Maple Trees?

In the maple species there are “hard” maples and “soft” maples. Soft maples will grow much faster than hard maples. The red maple tree falls into the soft category meaning it is fast growing tree which is good and bad.

Since it grows faster the limbs tend to be weaker, so wind and ice storms can damage them easier than a hard maple tree. After any storm you will want to inspect the tree for damage. If you spot storm damaged limbs take immediate action to remove them no matter what season it might be. This will prevent the damaged limb for hurting surrounding branches or possibly falling on something or someone.

You will also want to pay close attention to weak limbs and bad crotches (forks) as the tree matures. If you notice a bad fork off the main trunk you will want to prune this limb during the mid-summer months.

Dead limbs can be pruned anytime during the year as long as you are not cutting into “live” wood. If there is a situation when you have to remove more than just the dead wood it is best to avoid the peak sap producing time. But dead limbs can cause a safety issue if they were to fall, so it is best to take care of them when you notice them.

The time when you prune red maple trees is the same as any maple tree; mid-summer or in the fully dormant state just before the sap starts to run.

When To Trim Japanese Maple Trees?

There are 2 main types of Japanese maple trees; Upright Japanese maples and Laceleaf Japanese maples. You would prune the upright Japanese maple as you would a regular maple trees during mid-summer or during the fully dormant stage in the winter just before the sap starts to flow.

With the Laceleaf variety you want to be careful not to prune too much of the canopy or shell during the summer months because you can cause the trunk to get sunburned since it has very tender bark.

Dead limbs and suckers should be removed when you notice them any time of the year. You can also do light pruning most of the year.

You should avoid pruning for the couple of weeks as the leaves are coming out and for the couple of weeks when the leaves are turning color and falling off.

Can Maple Tree Be Pruned In The Fall?

Yes, but it is not the optimal time since the cuts will not have time to heal or harden off before winter hits.

The biggest issue is that when you prune a tree it can encourage new growth. If a plant puts on new growth just before the hard winter months, it can freeze the growth. All of this can stress the plant which can affect the growth in the following year.

The worst time to prune is when the sap Is flowing in the early spring.

Times When You Should Prune When It’s Not Optimal

Storm Damage: Storm damaged limbs should be tended to immediately regardless of the season. If a limb is cracked or broken off but still attach go ahead and prune the limb properly to allow it to start the healing process as soon as possible.

If a limb broke off the tree and left a stub, go ahead and properly cut the stub back to the trunk or nearest forked branch if the remaining limb will still get sunlight to the remaining leaves.

Dead Limbs: Dead limbs can be pruned anytime as long as you are not cutting into “live” wood. You will want to take care of dead limbs as they occur for safety reasons so that a limb doesn’t fall on property under the tree or an unsuspecting pedestrian.

Limbs in the Way: As the tree produces leaves for the new season it tends to weight the limb down. From time to time you might have older limbs that were just fine last year, now become in the way to walk under the tree. Cutting off a few limbs here and there is not an issue, so go ahead and remove the limbs that are blocking the way.

You can try to just take off some of the length to see if it will rise enough to not be a hazard anymore, by cutting the end of the limb off to a fork in the branch. If when you are just trimming the end off the limb causes the remaining leaves to all be “in the dark” you should go ahead and remove the whole limb back to the trunk. If a limb’s leaves do not get enough sunlight the limb will just die anyway.

Need to Transplant: Anytime you transplant a maple tree you will need to prune it. The amount you remove should be close to the same volume of roots cut. Usually this will be 1/3 to ½ of the plant. You will know if you cut out enough limbs because the leaves will be normal size and the plant will thrive. If you don’t prune out enough the leaves that form maybe much smaller than normal and the plant might take a long time to recover from the transplant.

Related Questions

Should You “Top” Maple Trees? No, but they will grow back. This puts a lot of stress on the plant and invites diseases through the big cuts. You see this with the softer maple like the silver maple more than with the harder maple trees that grow slower. This practice comes from the fact that soft maples tend to get storm damage easier since they grow so quickly.

Contrary to this belief it doesn’t really make the tree stronger, in fact the opposite happens because this practice weakens and stresses the tree overall which makes is susceptible to diseases which can ultimately kill the tree.

Can Over Pruning Kill a Tree? Usually not. There is always a slight chance with trees depending how severe the pruning was and the amount of care given afterwards.

If a tree is severely pruned it can take a couple of years to recover fully and much longer to outgrow the damage.

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Late Winter the Best Time to Prune Trees

BROOMFIELD, Colo. – Late winter, from mid-February through early March, is the best time to prune most trees. Trees are still dormant at this time of year and, unlike in early winter, wound closure will be rapid if pruning occurs just prior to the time new growth emerges.

“Pruning trees during the late dormant season reduces impacts on tree health, and builds a strong structure for our community trees in the long term,” said Keith Wood, urban and community forestry manager for the Colorado State Forest Service. Wood said that although some elms, maples, birch and walnut trees may visibly exude sap if pruned in the late winter or early spring, this should not harm the tree.

The CSFS offers the following tree pruning tips:

  • Know what you want to accomplish before you start pruning. Don’t remove any living branches without a good reason or specific objectives in mind.
  • Remove any torn, dead or broken branches.
  • Try to develop or maintain one dominant vertical top stem, or leader, and don’t cut off the tops of trees.
  • Space the main branches along the trunk, and prevent branches below the permanent canopy from growing upright or too large.
  • Always prune just outside the branch collar – the point where one branch leaves a larger one (or the trunk), often discerned by raised or wrinkled bark.
  • Limit pruning of newly planted trees to the removal of dead, damaged or crossing limbs, or those interfering with the main stem.
  • Avoid removing too many of a tree’s branches in any one year, as this will put undue stress on the tree.
  • Consider recycling pruned limbs by having them ground into mulch.

If a job requires running a chainsaw overhead or removing large branches or entire trees, Wood said it is best to contact an insured, ISA Certified Arborist. A list of these professionals can be found at http://www.isa-arbor.com.

The Best Times to Trim your Trees in CO and MI

Learn about The Best Times to Trim your Trees in Colorado and Michigan and other lawn care tips on the Fit Turf blog.

Instead of waiting until trees become dangerous before you trim their branches, you should find out the best time of year to trim trees in your area. There are different times of year that are better for trimming trees in different parts of the country, and the experts at Fit Turf know exactly when to trim trees around our headquarters in Michigan and Colorado. Find out when to tackle this hefty lawn care project in your state.

The Best Time to Trim Trees in The Denver-Metro Area

In Colorado, our experts agree that the late winter is the best time to trim your trees. From mid-February to early March, trees are still dormant from the cold, snowy weather, so they will be easier to prune; however, unlike at the beginning of winter, new growth is just about to begin again at this time, so the tree’s cuts will “heal” more quickly at this time. To ensure that your trees stay healthy and bounce back quickly after pruning, you should never remove more than 25 percent of a tree’s branches. In Colorado, you should also be aware that certain types of trees (like elms, maples, birch and walnut trees) will leak sap when you cut them, but this won’t harm the rest of the tree.

The Best Time to Trim Trees in the Detroit-Metro Area

Michigan trees do best when they’re trimmed from the late fall to early spring. This is because the tree is dormant during these colder months, which last a bit longer in Michigan than in other states. The dormant tree will experience much less stress when it’s pruned, and because the leaves won’t be on the tree’s branches, it will be easier to see where to cut. Insects and other pests aren’t active during these cold months, so you also won’t have to worry about infestation. Most importantly, the worst time to prune a tree in the Detroit-metro area is in the late spring or summer, when trees are experiencing the most growth.

Maple Tree Pruning – How And When To Prune A Maple Tree

The tree in the backyard that blazes with red, orange and yellow foliage in autumn is most likely a maple. Maple trees are known for their brilliant fall color as well as the ease with which they “bleed” sap. The species’ tendency to lose sap from wounds makes gardeners question the wisdom of pruning maple trees. However, maple tree pruning is an essential part of maple tree maintenance. It’s important to learn how to prune maple trees and to pick the best time for pruning maples.

When to Prune a Maple Tree

Many gardeners are confused about when to prune a maple tree. In late winter, when the days are warm and the nights are cold, root pressure causes sap to flow from any wound made in the bark of the tree. This makes it look as if the tree is suffering.

However, maple tree pruning in winter generally won’t hurt a mature tree. You would have to remove an entire limb for the loss of sap to negatively impact a fully grown tree. If the tree is just a sapling, however, loss of sap may cause problems.

You can avoid this issue if you wait until summer to prune maples. Once the leaf buds open, the sap is no longer under pressure and won’t leak out from pruning wounds. For this reason, many gardeners say that the best time for pruning maples is in summer after the tree is fully in leaf.

How to Prune Maple Trees

Gardeners trim maple trees for a variety of reasons. Regular maple tree pruning helps keep a tree the desired size and stops a tree from encroaching on its neighbors.

Pruning also assists the tree develop a sound branch structure. Carefully removing branches can reduce or eliminate structural issues in a tree. It can also open up the center of the tree to let sun and air move through the canopy. This prevents certain types of diseases.

When you are pruning maple trees, it is always a good idea to remove broken, diseased or dead branches. Otherwise, the decay-producing fungi can infect healthy parts of the trees.

Pruning Maple Trees

Learn about the benefits of pruning maple trees.

Caring for your maple trees can require a bit of work, but the rewards are worth it. You’ll have beautiful, lush maples that can produce delicious maple syrup. Pruning is one of the most important parts of taking care of your trees. Pruning maple trees not only helps fight off maple tree diseases, but also promotes tree health and structure.

When to Prune Maple Trees

Keeping your maple trees healthy is important for tree growth and syrup production. Learn when and how to start pruning maple trees.

Pruning should be done in late winter or early spring. Pruning maple trees during the dormant season will help your trees with new growth in the spring when they bloom. You can also prune in the summer if you want to slow the growth of certain branches. This is done to shape the tree, and get rid of any defective or dead branches.

Don’t prune your maple trees in the fall. Wet fallen leaves in autumn are a breeding ground for many maple tree diseases. Pruning maple trees in the fall will only expose them to spores from the fungal diseases.

1. Equip yourself with the right safety equipment. Wear gardening gloves and eye protection.

2. Decide on the shape and direction you want your tree to grow.

3. Try not to remove any major (parent) branches of the maple tree. Remove damaged or dead branches. Make thinning cuts to parts of the tree that are full of branches. These cuts should be made slightly above the parent branch. Use pruners for smaller branches. Use loppers for medium branches. Only prune up to 25 percent of your tree’s growth.

4. If you’re going to cut off large branches, use a pruning saw. Undercut the large limb about 1/4 of the way through, between six and 12 inches from the trunk. Then cut through the top of the branch, about one inch beyond the first cut. Remove the final stub right above the branch collar. The branch collar is the round, stubby part that forms around the base of the branch. It’s vital not to cut into the branch collar. Once the cut is made to the tree, the area above the branch collar needs to heal to prevent disease and rot.

When you’re pruning maple trees, the trees may start to leak. Don’t worry, it’s just sap and it’s completely normal. Maple trees normally bleed sap after pruning in the winter. It’s less likely to happen in the summer or late spring.

The Best Time to Prune Maple Trees

Have your maple trees become unruly?

The holidays are right around the corner and if your home is anything like mine, you are preparing for family and friends to visit. Along with the preparation inside the home, there is preparation going on outside the home that is beyond putting the Christmas lights up. One of those is tree care.

I love the maple trees in the back corner of my land. They offer such wonderful shade and beauty. There are two times of year when you can prune your maple trees and right now is one of those times.

Winter Pruning

Here are a few reasons why winter pruning is great for the health of your tree.

  • The tree is dormant meaning that while the tree is alive, it is not growing.
  • During the winter the leaves are no longer in the way making it easier to see the trees structure.
  • Winter pruning encourages new growth.
  • Due to the trees dormancy, the tree is no longer has lavish sap.

Summer Pruning

Another optimal time to prune maple trees is during the summer months. Here are the benefits to pruning in the summer.

  • Unlike during winter, during the summer all the leaves are intact making it easier to shape the tree.
  • According to Home Gardening Ideas, summer pruning does not encourage new growth.

Whether you chose to prune in the summer or winter really depends on if you would like your tree to continue growing. When is your favorite time to prune your trees?

Maple tree pruning may be done in the spring, with the best months to prune being the time immediately after leaves appear. If you prune the tree in the winter or springtime, the sap bleeds or runs out. While this won’t harm the tree, it doesn’t look very pretty, so prune the tree in late spring or summer if you can.

Maple Tree Pruning Tips

Most experts agree that you shouldn’t prune more than 15 percent of the maple tree in any one year. It’s better to prune a little bit each year than to prune a lot one year.

Winter Tips

Even though the tree will be fully leafed out during the actual pruning, careful planning before foliage season can be a big help. During the winter, when the deciduous leaves have fallen, inspect the bare branches of your maple. Note any limbs that should be removed and tie a ribbon around the lower ones. You can use a ceiling painting wand (or a brush tied to a stick) to mark higher limbs that need pruning. Simply use any house paint sitting around to do the marking.

Selective pruning that opens up the canopy mitigates disease and pest risks. Allowing good air circulation through the branches is critical to propagating tree health.

What to Prune

You can prune off little twigs coming off the stem of the maple tree. By pruning off the little branches, the tree will put further energy into growing up and out into the larger branches. Note any split or U-shaped limbs. They may not be much trouble for a young tree, but they will become prominent weak areas that can kill or shorten a tree’s lifespan as it matures. These issues can become difficult or impossible to remedy later on.

Trim away side shoots and any branches that hinder others, interfere/scrap other branches and any limbs that are diseased, broken or unthrifty. Dead branches need to be cut away as well. Remember to clear away any of the debris that falls around the base. Rake up leaves and twigs- this is where diseases and pests proliferate. When fungus takes hold of a dead or weak limb, it can spread to the main tree.

How to Prune

Always use sharpened pruning shears or loppers specifically designed to cut through tree branches. Make cuts at an angle, and make the cut as close to the living part of the tree as you can.


Pruning supply needs vary by individual. The basics include:

  • Pruning shears
  • Pole saw (electric or manual)
  • Long- handled loppers
  • Japanese pruning saw

Basic Pruning Instructions

Prune branches off that need removal following these simple instructions.

  1. Before trimming, identify the branches that need to be removed: dead limbs, weak/deformed branches, suckers or water sprouts, rubbing limbs, “U” shaped branches, and structurally weak crotches.
  2. Cut small branches at a slight angle. Always use clean, sharp shears of a proper cutting strength. If you use the shears on diseased limbs disinfect them (10% regular bleach solution) before continuing.
  3. Prune as near to the trunk as you can. Shear the branch with a clean cut.
  4. Discard the trimmed branch in a compost pile.

Canopy and Understory Pruning

Pruning young maples can be done with ease. Older trees will generally require a professional, but cutting lower level and smaller branches can be accomplished by the home owner. Do not remove too many large limbs on mature trees.

  1. Opening the canopy is done in young trees. Maple trees have a rounded canopy, unlike the leader limbs of many evergreens. Aim for an open and relatively symmetrical canopy branching system that allows for a pleasing shape and good air circulation. Remember not to overdue the pruning. You can always remove limbs but you can’t glue them back!
  2. Cut medium to small branches with the shears (shears are designed to cut a specific diameter- package labels specify cutting power). Cut the branch close to the trunk – just before the growth bud.
  3. Trim smaller shoots with the shears by snipping at a slight angle.
  4. Use an arborist saw or pole saw to trim larger limbs. Cut the limb at the crotch. Locate the growth swelling and make the cut just above this area. Cut parallel to the angle of the growth swelling. Always be aware of where these limbs will land once trimmed!
  5. Discard the cut limbs in a compost pile. Large maple limbs make great firewood. Use them for a campfire!
  6. Understory pruning is easy. Trim away the lower branches and shoots on young maples. This will help to shape the trunk to allow for walking clearance under the branches as the tree grows.

Safety note: Canopy pruning on mature maple trees involves significant risk to the arborist. Use pole saws to prune high-set branches, but be wary of dead fall. Limbs that fall from high up the trunk can cause serious injury. Never attempt to climb the tree unless you are ready to use correct safety equipment.

Special Pruning

Maple trees can provide more than just shade and beauty. Try shaping and pruning certain desirable branches if you would like to plan for a swing, tree house or unique tree structure. Remember to look for limbs that are sturdy and connected to the trunk properly (crotches should not be split, or in a weak “U”).

Young, pliable branches can be bent and guided. Gently bend the branch into the desired angle and use a rope with stakes To hold it in the right position. Periodically check on the stake and be sure the rope is not cutting into the growing branch.

Caring for Equipment

After pruning trees, dip the pruning shears and other equipment into a bucket filled with one tablespoon of bleach to a gallon (or wipe the blade with rubbing alcohol) of water. Rinse off, dry and store carefully. The bleach and water solution kills any bacteria or fungi that may be on the equipment. These can infect the next plant you trim if they’re not cleaned properly.

Most disinfecting agents are damaging to the metal of tools. Only disinfect the blades if you have trimmed known diseased plants. Always wipe clean any disinfectant residue to maintain your tools. Never store metal tools that are damp.

Pruning Problems and Questions

Several very common problems and questions arise when discussing maple tree pruning.

Weepy Trees

If you pruned your maple trees and the next day there’s liquid running from the pruning spots, don’t panic. The liquid is simply sap. While it’s more likely to run during the fall and early winter, it can run at any time of year. The pruned areas won’t heal as quickly if the sap is flowing freely, which is why many arborists recommend waiting until the late spring or summer when the sap is least likely to run before pruning.

Sap Ooze

You may also see your maple trees oozing sap during other times of the year. Check the trunk for teeth marks, particularly in the fall or winter. Squirrels and other creatures love the sweet taste of maple sap and may even bite the trunk to start the sap flowing if they know what sweet taste is in store for them. It won’t harm the tree, but it can be scary if you don’t know what the stuff is running out of your tree.

Trees Near Power Lines

It’s best to avoid planting trees directly under power lines, but if your tree was planted before you moved into your home, or it’s grown more aggressively and vigorously than planned, you need to decide whether or not it should be pruned. If the utility lines are publicly owned, the utility company will prune the tree. They will probably prune it very drastically. They have to; branches that entangle power lines can pull down the lines in a storm, disrupting service for many. Don’t try to trim trees near power lines yourself. Call the utility company or a tree service.

Over Pruning

Unfortunately, if you got carried away and over pruned your tree, there’s nothing you can do right now. It’s like getting a bad haircut; you have to wait for it to grow back. Hopefully you didn’t prune away too many branches and weakened the tree. Remind yourself the next time you reach for your pruning shears not to go overboard!

Painting the Pruned Spots

In years past, horticulturist recommended painting over or sealing the trunk of the tree where the branches were pruned off. Newer research indicates that this isn’t necessary; the tree heals itself effectively, sealing over the pruned areas and creating its own scar. So there’s no need to bandage the pruned areas or paint them. Just leave the pruned areas alone and let nature seal it off.

Maintain Your Maple

Maple trees do not need much care to provide a striking and majestic focal point to any landscape. Whether you are maintaining healthy stands of maples for sugaring, or you are pampering a single shade tree, following a few simple pruning steps will keep your maples in tip top form.

Pruning trees and shrubs

The rule of thumb to follow when pruning trees and shrubs is: “If you have no good reason to prune, don’t”. Most trees and shrubs have a natural form to them and may do better and look better if left alone. Each kind of tree has its own characteristic shape or growth habit and when pruning, you should try to maintain that habit. There are times, though, when pruning must be done and proper procedures should be followed.

How pruning affects plant growth

Pruning trees in late winter and early spring before growth starts reduces the number of leaves produced the coming year. Less water and nutrients will be required because there is reduced top growth. The strong root system below supplying a reduced top, results in strong, succulent, rapidly growing shoots. This invigorating effect is present throughout the tree, but is most noticeable on those limbs which have been most severely pruned.

When a branch is pruned back, new shoots arise near the cut. The new shoots generally grow in the same direction that the buds were pointing. Thus, a bud on the inside of a branch will grow towards the centre of the tree and an outward facing bud will grow away from the centre of the tree.

Reasons for pruning

  • Pruning at planting time:
    • just after transplanting, the tops should be pruned back to compensate for the loss of roots and to begin training the tree. This should not exceed one-third of the plants total top growth.
  • Training:
    • to develop a strong framework to withstand winds, a tree should be pruned to a few strong limbs spaced well apart, up, down and around the trunk.
    • to develop a shade tree with limbs coming off the trunk at a height greater than 1.6 to 2.4 metres, lower branches should be pruned off. Ideally pruning should be done over an extended period of time as the tree grows in height. If done all at once this can result in a weak, spindly tree that needs staking. If you are going to prune all at once it is best to prune those lower branches to short stubs. These stubs will eventually be removed. The short stubs act as sap drawers, putting out leafy shoots which manufacture food and draw up water and minerals resulting in a stouter, stronger trunk. These stubbed branches must be kept pruned back and can be removed completely after permanent scaffold branches (main crown) have been established.
  • Tree health:
    • prune to eliminate limbs with weak crotches that arise from the trunk at acute angles.
    • prune to eliminate limbs that cross each other or compete for the same space in the trees crown.
    • prune to eliminate dead and diseased branches to improve the appearance of the tree and prevent entrance and spread of diseases and insects.
    • prune to revitalize older trees by pruning out part of the crown of the tree, reducing the leaf area that the root system has to supply. More vigorous growth results in the remaining branches.
    • prune to increase air circulation through the tree both for the trees benefit and to increase air flow into the landscape. More sunlight gets through the tree which is beneficial for lawn growth below.
  • Safety:
    • dead, broken, weak or split branches, or low hanging branches which might be a hazard to people, vehicles or buildings should be removed.

Pruning tools

Good quality pruning tools make a difference when pruning trees and shrubs. When buying tools, usually you get what you pay for, so cheaper tools….usually are! Hand or pole mounted versions of secateurs and pruning saws are available. For large limbs, a bucksaw can be used.

Chainsaws are fast and efficient but do not make clean cuts which results in slow wound healing.

  • Scissor action secateurs are the best type for small branches and make cleaner cuts than anvil action types.
  • Pruning saws are compact and specially designed for heavy duty pruning in tight spaces.
  • Lopping shears are used for larger branches and come with different handle lengths. Try to buy scissor action lopers rather than anvil action ones.

Pruning deciduous trees

In general, deciduous trees and shrubs should be pruned when they are dormant, preferably in early spring just before growth starts. At this time, wound healing will begin almost at once and it will be most rapid. Dormant pruning will have less effect on the growth of trees than pruning when the tree is in active growth. Another advantage of dormant pruning with deciduous trees is that it is easier to select branches which should be removed when the leaves are gone.

Dead limbs and those lacking in vigour can be pruned in mid-summer when they are easier to locate.

Exceptions to the dormant pruning rule are maple, birch and elm which should be pruned when actively growing in mid-summer. When pruned in early spring, these species may lose excessive amounts of sap. Pruning of Maple and Birch should not be done too late in the fall either, as wounds will not have a chance to heal before winter. Elm trees should not be pruned between April 15 and August 30, to prevent the spread of Dutch Elm Disease.

When pruning deciduous trees, make all cuts close to, and parallel to, the trunk or crotch of the tree. In order to avoid damage to the main limb or trunk when cutting large branches, use the 3-step method illustrated below:

  • The first cut is made part way through the branch on the underside, a short distance from the trunk to which it is attached.
  • A second cut is made from the top down, five to eight centimetres further out the branch from the 1st cut. The weight of the branch will cause it to break free and fall outward without tearing any bark.
  • The third and final cut is made close to the trunk so as not to leave a stub. When removing live or dead branches, avoid cutting into the callus tissue which has formed at the base of the branch. The tree will not be able to heal properly without this growing tissue intact.

Pruning evergreens

Evergreens require little pruning in most cases. For pruning purposes, two types of evergreens are recognized: a) those that produce their branches in whorls such as spruce, pine and fir (conifers), and b) those such as juniper and cedar that do not exhibit the whorled habit.

Most trees in the first group are grown as single trunk trees giving them a pyramidal form. In this case the removal of entire branches will leave gaps and should only be done if the branch is dead or diseased. Pruning of these evergreens should be confined to trimming back new growth at the tips of the branches.

When this pattern of pruning is practiced annually, the result can be a noticeable increase in the density of the tree.

  • Pines: Most pines are best pruned in mid-June before the needles start to unfold. At this time, the new growth looks like candles. *It should be noted that the date of pruning will depend on the year and could be different each year. When these terminal shoots are soft they may be cut back to one-half to one-third of their length. This will control the length of subsequent growth for that season. New terminal buds will form at the cut ends by the end of the growing season and growth the following year will spread out from those points. (see below).
  • Spruce and Fir: If it is a matter of shortening shoot growth, spruce can be pruned by cutting the shoot back to a lateral bud in early spring before growth starts. (Pruning should be done in mid-May to early June, before new buds for next year’s growth have been formed.) Growth will continue on from that bud as the season progresses. Density pruning of spruce and fir is best carried out after the growing points have elongated (see below). To control growth, prune half of the new growth early in the spring when the new growth has extended. This will increase the density of the tree much the same way as with the pines.
  • Cedar and Juniper: Evergreens with soft growth such as Junipers and Cedars may be pruned by clipping back new growth preferably in early spring to mid-June. Clipping back the most vigorous branches once or twice a season will keep the plant dense without destroying the natural appearance.
  • Damaged Terminal Leaders: If a terminal branch of spruce, pine or fir is damaged in some way and must be removed, a lateral branch should be trained upwards to replace it. A strong branch from the uppermost whorl should be selected and carefully tied up to a stake like a splint. About 17 centimetres (cm) should be cut off the remaining branches of the whorl to direct more growth to the new leader. When two or more leaders are present, all but the strongest should be removed when the tree is relatively young.

Diseased Branches: When removing diseased material, tools should be disinfected in a five per cent Javex or alcohol solution between each cut. Always cut back to healthy wood.

Wound Dressing: The treatment of tree wounds with dressings is a controversial subject. While dressings do protect against the invasion of water, disease and insects, they also slow down the healing process. It is recommended that dressings only be used on cuts with a diameter over 15 cm. Be sure to use only dressings that are recommended for trees. Do not use ordinary paints!

Field shelterbelt pruning

Maintenance pruning of shelterbelts is practiced for three main reasons. Dead, diseased or storm damaged branches are removed for reasons of safety, appearance, and disease control. Secondly, branches that interfere with powerlines, machinery operations or pose a threat to property need to be removed.

Finally pruning is carried out to improve the appearance of the shelterbelt by removing suckers and interfering or wide-spreading branches. However, unlike shade trees which are pruned up to accent their form, in shelterbelts the removal of lower branches should be done only if there is a need to change the density of the windbreak.

The recommended time for pruning is during the winter or early spring in order to lessen the damage of infection. However, in practice it may be more desirable to prune in mid-summer when the trees are in full leaf in order to easily locate dead limbs or branches lacking in vigour.

Mid-summer is also the best time to prune trees such as maple and birch. When pruned in spring these species may lose excessive amounts of sap. However, pruning should not be done too late in the fall as wounds will not have a chance to heal before winter. Pruning of dead branches can be done at any time of the year since no living tissue is affected.

In pruning, appraise the tree before cutting in order to select the branches that will serve as the main structure of the tree. Make all cuts close to and parallel to the trunk or crotch.

When pruning diseased parts, remove 15 cm or more below any evidence of the disease which usually means going back to a living lateral branch or to the trunk of the tree. In order to avoid damage to the main limb or trunk when cutting large branches, use the 3-step cutting method.

The first cut is made part way through the branch on the underside a short distance from the limb or trunk to which it is attached.

The second cut is then made from the top down 2-3 inches further out on the branch. The weight of the branch will cause it to break free and fall outwards without tearing any bark.

The third and final cut is then made reasonably flush with the limb or trunk in order to avoid leaving a stub. At the same time it is important to avoid cutting into the limb or trunk. Leaving a minimum of exposed surface will allow the cut to heal over in time.

When removing dead branches avoid cutting into the callus tissue which has formed at the base of the branch so that living tissue is not exposed.

In order to make sharp, clean cuts, ensure that tools are in good condition. When removing diseased material, tools should be disinfected in a javex or alcohol solution between each cut.

The treatment of tree wounds with dressings is a contested subject. While dressings protect against invasion of water, diseases and insects, they also impede the healing process. If they are used, obtain one of several commercial products. Do not use ordinary paints.

Maintenance pruning should be done such that the natural form of the tree is followed or restored while removing all dead, diseased, broken and crossed branches. In order to maintain shelterbelt density at all levels, remove only what is required. In any case, never remove more than 25 per cent of the producing potential of the tree in any one season.

Caragana pruning in shelterbelts

Side-trimming a caragana shelterbelt encourages new growth and prolongs its lifespan. Mature caragana stands should not be trimmed to less than three metres in width.

Top-trimming a caragana shelterbelt reduces windthrow of old, weak branches and encourages new growth.

Trimming and pruning must be done during the dormant period (October-April) and is best done during cold weather since cleaner cutting results.

Cutting a caragana shelterbelt back to ground level encourages new growth and prolongs shelterbelt life. Special caution should be taken on erosive soils to protect the soil with other conservation measures during the period of shelterbelt regrowth.

Control of perennial grass in shelterbelts by cultivation or herbicides revitalizes belts by reducing root-binding of trees and shrubs.

Replacement of any shelterbelts is recommended only if the shelterbelt has seriously deteriorated. Caragana shelterbelts will seldom need to be replaced while old shelterbelts containing short-lived tree species such as Manitoba maple and Siberian elm are more likely to need replacements.

The replacement shelterbelt should be planted leeward of the existing shelterbelt prior to the removal of the old belt. The new belt should be at least six metres from the edge of an existing caragana shelterbelt and at least 10 metres from the edge of an existing tree shelterbelt. Regrowth from the old shelterbelt is minimized when removal is done during the summer.

Thinning and pruning of deadwood is encouraged if an effective shelterbelt can be maintained. Removal of live, healthy material is not renovation since it reduces shelterbelt protection and damages the shelterbelt.

Root-pruning is not a renovation measure as it increases stress to the shelterbelt and does not contribute to the protection value of the shelterbelt.

Root Pruning of Siberian elms

Field shelterbelts play an important role in protecting farmland from wind erosion. They also increase snow catch, moderate air temperatures, reduce evaporation and increase overall crop yield. Although generally beneficial, shelterbelts do compete with adjacent crops for moisture and nutrients. Siberian elm can rob moisture needed by crops due to its extensive lateral root system. Root pruning, the practice of severing lateral roots, can reduce the effects of Siberian elm root competition on nearby crops.

H=Height of Shelterbelt

Root pruning can be done using a subsoiler. The subsoiler is pulled through the ground parallel to the shelterbelt, cutting the roots. To reduce stress on the trees, only one side of the shelterbelt should be pruned each year. This should be done during the spring or fall while the trees are dormant.

Root pruning should be done no closer than three-quarters of the height of the trees away from the shelterbelt, as illustrated below, to a depth of 60 cm. It should be repeated every two to three years to control new root growth. Pruning too close or too often could harm or kill the shelterbelt, especially if it is an older belt or under drought stress. During drought periods, root pruning should be discontinued completely.

While root pruning does not completely eliminate competition between field shelterbelts and crops, it reduces the competition and is one method which can be used by farmers to increase the effectiveness of their shelterbelts.

Repair of snow and ice damage to trees

Excessive amounts of snow and ice can cause injury to farmstead trees and shrubs. Unfortunately, before storms occur little can be done to prevent damage. Often, however, with proper care damaged trees can be restored.

Several tree species are generally more susceptible to ice and snow damage than others. Deciduous trees with soft brittle wood such as Manitoba maple, Siberian elm, poplar, birch and willow may be seriously damaged by ice and snow. Coniferous trees are not as prone to damage, however, multi-stemmed low growing evergreens such as junipers tend to break or spread under a load of snow.

When large quantities of snow and ice are present on tree limbs, several steps can be taken to prevent damage. As ice coatings may increase the weight of a branch up to 40 times, improper removal of ice or snow often increases damage. Ice laden branches should be propped up with suitable materials and knocking ice off branches where breakage may occur should be avoided. Snow may be gently brushed away if it has not frozen to the branches.

Once damage has occurred trees should be examined carefully to determine the extent of the injury. If damage is not too extensive and the tree is worth saving, proper pruning and/or repair of affected trees should be employed. If damage is extensive the tree should be removed and replaced with an appropriate species. When large branches or the entire tree is damaged severely enough to endanger human life and property, the pruning should be done as quickly as possible, otherwise pruning and/or repair can be delayed until spring.

When breakage has occurred but the branch has not split to any great extent, remedial action can be taken to avoid further splitting and the entry of moisture and disease organisms. The split crotch can be brought together and retained in position by a cable extending from the trunk to the limb. To further reinforce the repair, bolts with washers, should be inserted through the split area every six to eight inches down the length of the split.

Severely damaged branches should be pruned back to the next lower crotch in early spring. Trees which bleed readily (birch, maple) should not be pruned until leaves appear. It is important to make a smooth cut in sound wood so proper healing can be initiated.

Steps (A to E) to be taken in removal of large damaged branch

All cuts should be made flush to the trunk, although retention of a small lip as illustrated (E), will speed healing. Never leave a stub as they lead to proliferation of water sprouts or suckers. When the main stem or leader has been damaged, it should be cut off flush with a smaller branch that is growing in the desired direction. Following pruning, saw cuts should be treated, and although not essential, paring the ragged surface of a saw cut will accelerate healing.

Generally, healing will occur quicker if no tree wound dressing is applied. However, if disease and insects are a problem in the area, all cuts with diameters of one inch or more should be sealed by painting with a tree wound compound. There is some evidence that the application of a complete fertilizer in late April or May will help stimulate new growth and speed recovery.

If ice and snow damage is a common occurrence in your area, it may be worth considering some preventative pruning of high value specimen trees. Branches with weak crotches or those which are weakened by disease or insects should be.

Date modified: 2015-08-10

When to prune trees and shrubs? Wait till after the leaves fall.

Pruning too soon can harm your trees and shrubs.So, when it comes to fall pruning, procrastination is the way to go.

Take my neighbor. I saw him walking his dog last week on a perfect warm September morning. We chatted for a while, and as we parted, he asked, “Is this a good time for me to prune my trees? I want to do some gardening while the weather is mild.”

“Wait a bit,” I replied. Although pruning a little branch or two may be OK, bigger tasks like thinning the crown or cutting a big limb can wait.

Reasons to procrastinate

Why delay? Consider these points:

  • In early fall, pruning wounds close more slowly and plants are more at risk for fungal diseases than at other times of year. For most trees, the best time for major pruning is late winter to early spring because wounds close faster.
  • Pruning in late summer and early fall may also stimulate new growth, which has little time to harden before cold weather comes. The cold can harm this tender new growth, and the tree may need more pruning in spring to remove the damage.
  • If you want to prune in fall, wait until trees drop their leaves and are dormant—usually October or November. After leaf drop, you can see the tree’s structure and identify disease and insect problems more easily. Dormancy (especially late winter to early spring) is also a good time to prune evergreens because vigorous spring growth will hide pruning wounds.
  • If you want to transplant transplant a small tree the next spring, late fall (October/November) is a good time for root pruning. This pruning technique stimulates new root growth at the cuts and helps a newly transplanted tree get established in its new location.
  • One exception to the no-fall-pruning advice is that you should remove dead, diseased, and damaged wood as soon as possible — for tree health and your safety. Take proper safety precautions at all times. Hire a professional arborist to remove big limbs, high branches, and any other tree job that you’re not prepared to do.

When I saw my neighbor later that day, he was lounging on his porch. “I’m waiting to prune,” he said, waving at me.

Do you prune in fall?

What’s your experience with fall pruning?

Penelope O’Sullivan is one of nine garden writers who blog regularly at Diggin’ It. She is the author of “The Homeowner’s Complete Tree & Shrub Handbook” and 11 more books on trees, shrubs, hedges, flowers, herbs, and garden design. She is a guest speaker on many gardening topics, has written and scouted for numerous magazines, and owns a garden design business in New Hampshire. Her latest book, “The Pruning Answer Book,” co-authored with Lewis Hill, will be published in March 2011. To read more by Penny, .

The wrong time to trim trees

Summer’s the wrong time to be trimming trees

Rich in Fairfax Station writes, “I help a neighbor 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 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. During summer’s heat, having to produce 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 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.

Warning: 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 branch. 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.

“I am shocked, shocked, to find mushrooms on wood mulch!”

Vicki and Danny in Rockville write, “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. 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 (but not the good kind)

The images Dwight sent show a severe infestation of bagworms on an evergreen. (Courtesy Mike McGrath)

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 fertilizers or — ahem — mulching with chipped-up pallets from China spray painted some God-awful color.

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 a 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 afterward.

In the long term, avoid using chemically-based plant foods and stop using mulches that stress your plants. Switch to compost or pine straw. A healthy, happy plant rarely suffers these kinds of attacks.

Rubber baby buggy mulch

When I sent Dwight in Randallstown my email advising him to get rid of the wood mulch that had made his plants so attractive to bagworms, his reply — and I could not make this up — was “Okay — so my next step is to go to black rubber mulch?”

Oy! I should have listened to my mother and taken that job in the fish canning factory back when I was 15!

No, no, no, Dwight. Black rubber mulch is made from chipped-up old car tires. It’s potentially toxic, a definite fire hazard and definitely stinks in the summer heat. Stop letting people with waste disposal problems use your landscape as a landfill, and switch to a mulch that prevents weeds without nasty side effects, like compost, pine straw or pine fines.

Artichokes: Let George do it!

John in Burke emailed me to say, “I have artichoke bushes that have gone through two winters now. They are very healthy looking and growing well, but I can’t seem to get them to produce actual artichokes. Any suggestions?”

John countered with, “you see artichokes all over Mt. Vernon; that’s where I bought my seedlings.”

This is a great lesson in what experts can do when they have greenhouses, cold frames, hired help and lots of knowledge, John. Not to mention that Washington himself was immensely talented at getting plants to thrive outside their normal range. In other words, although artichokes can technically be grown in the mid-Atlantic, it is a laborious and involved two-year process that requires constant attention. It is not a “plant it and forget it” project.

I suggested that he contact the gardeners at Mt. Vernon to see what kind of tricks and techniques they use, as their advice would jibe perfectly with his own microclimate. Also, I sent him this article from the Connecticut Agriculture Extension Service that provides some solid advice on how to try growing artichokes outside of their normal range and an article I wrote on the topic for my Public Radio show some years back.

But, as I say in that article, there’s a darn good reason that virtually all American artichokes are grown in a single county in Southern California.

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