Tree trimming or pruning, when involving all but very large limbs and branches, is a task that can be handled by the average homeowner. When to prune is important. While it can technically be done at any time of the year, arborists recommend trimming trees in the late winter or early spring while they are dormant (i.e. not growing). This helps reduce or eliminate the amount of sap flow from the stump, allowing the tree to retain more of its nutrients.
TIP: Our expert gardening advisor, Karen Thurber adds, "Pruning trees while they are young is important to establish good structure. Begin to shape and prune your tree 1 to 2 years after planting."
WARNING: Check with authorities to see if your tree qualifies as a heritage trees, in which case you need a permit to cut it. You can pay hefty fines for cutting or trimming heritage trees without permission.
Tools of the Trade
Pruning shears – Available in both scissor and anvil action models, the scissor design is often preferred because it makes a cleaner cut.
Lopping shears – Operated with both hands, this scissor-action tool can slice through branches up to 2 inches in diameter.
Pole pruner – Good for reaching higher branches.
Rope saw – Allows cutting of branches located higher on the tree while you remain on the ground.
Portable buck saw – Light weight but very strong.
Chainsaw – For larger jobs, and intended for use by professionals or highly experienced homeowners only.
Hard hat, gloves and safety glasses – For personal protection.
TIP: Karen recommends, "Pruning tools should be regularly sharpened to ensure a clean cut. A clean cut will heal quickly, reducing the stress on the tree and the opportunities for diseases and insects."
There are several general approaches to pruning, each for a specific purpose, including:
Cleaning – removing dead, diseased or weak branches from the crown of a tree
Thinning – removing branches to allow more light to penetrate, reducing stress on heavy limbs and encouraging retention of the tree’s natural shape, removing crossing branches that may rub on each other
Raising – removing lower branches to provide clearings for buildings, vehicles, pedestrians and views
Reduction – cutting back tree limbs to reduce the size of the tree and make room for utility lines
Making the Cut
Select a spot about 3 inches from the collar of the branch (the thickened, collar-like place where the parent and child limb intersect) and make a cut about 1/3 of the way through the branch. This will prevent the branch, when severed, from tearing through the collar or the parent branch and harming future growth. Make this first cut on the underside of the limb.
Cut slightly beyond this first slice and cut straight through the branch to be removed.
Make a final cut through the remaining portion of the branch, as near to the collar as possible, without touching the collar itself.
To Seal or Not to Seal
For the most part, it’s not necessary to seal the stump left after tree trimming. Nature will do this on its own. There are exceptions however. Trees such as oak, birch and elm are particularly fragile and prone to disease. You may wish to use a non-asphalt based pruning sealer for these, as well as for any fresh stumps on trees in very dry climates.
TIP: Karen advises, "Do not prune Oak trees from early March through July. Oak trees are highly susceptible to the disease oak wilt which is spread by sap feeding beetles that are active during this time."
When to Call in an Expert
If you’re inexperienced using the tools needed for the job that must be done, it's time to call a professional arborist, especially with power tools, such as chainsaws or others that harbor the chance for serious injury.
Also, if the limbs you need to remove are especially heavy. When it’s possible for the limb to fall improperly and hurt you or an adjacent structure.
Call in a pro if the limbs that need removing are too high on the tree for you to reach. It takes some skill to climb a tree or use the extended tools required for such a job. Also, never use a ladder for these jobs.
If the tree is close to a power line, don't try to do this yourself.
How Much Do Tree Trimming Professionals Charge?
Professional tree trimmers charge, on average, between $50 and $90 per hour. Good ones should be members of a professional association such as the International Society of Arboriculture (ISA) and be certified by that association’s Certified Arborist program. They should also have proof of insurance, a list of references, and give you a written estimate before beginning work.