How to Prune Correctly and Mistakes to Avoid
Pruning practices can make or break a tree’s appearance and health. Be sure to follow best practices when doing tree maintenance for customers.
September 14, 2023
Pruning is an important task in keeping plants healthy. It both reduces and enhances the plant’s shape, removes impediments, removes dead growth, and opens the canopy. Before you prune, you should always have a goal, such as removing dead limbs or increasing flower production.
Poor pruning can lead to tree health decline and poor aesthetics. Each pruning cut creates a wound. A correct pruning cut allows the tree to seal off the wounded area and prevents insects and disease from intruding. If you prune incorrectly, you can permanently damage the tree. Take your time, especially when first starting out, as you cannot fix poor cuts. The goal should be to make as few cuts as possible to achieve your desired results.
Some materials you need for the job include a pruning saw, pole pruner for distance cuts, hand pruner, and a tripod ladder. Consider also investing in hook and blade long handle pruners to use for leverage; these can cut larger branches than a hand pruner could and work faster than a pruning saw.
Timing Your Services
Timing your pruning services will depend on your geography’s seasonality. Ensure you’re pruning at the opportune time for the tree varieties you are working with. Avoid pruning in the late fall, as pruning can stimulate growth. That growth will take up precious stored energy reserves, which could lead to plant death when the temperatures drop significantly. Fall pruning can also result in fewer spring blooms because it can remove buds that grew during summer, which can throw off plant energy expenditure as it works to replace what was removed when spring arrives.
Winter pruning is ideal, because in many regions the plants are dormant, and they experience less stress. Typically, there’s less foliage, so you can better see the branch structure. However, if you’re pruning a spring-flowering tree, wait until the plant has bloomed before cutting to avoid removing buds.
When trees are pruned in the late spring and summer seasons, you risk the tree losing too many leaves and not producing enough energy. Summer is also drought season, which can lead to extra plant stress and sunscald on bark if a tree is heavily pruned.
Whatever your geography and weather, be sure to avoid pruning during high seasons of pests and disease. If you prune when plants are most vulnerable, the plants can suffer from airborne and insect-spread disease. Cuts can attract certain pests, like beetles, so avoid pruning during hot weather when these pests are more active.
Avoid These Mistakes
Flush cuts happen when you cut a branch flush with the trunk of the tree, removing the branch collar, or the area with a small bump near the base of the branch that has specialized cells that help heal the wound. The collar looks like a small bump where the branch meets the trunk. These kinds of cuts prevent the tree from callusing over the cut to seal it to create a barrier from disease.
Pro Tip: Avoid a flush cut by cutting just beyond the branch collar so it can grow over the wound and seal it. Don’t get too close to the main trunk.
Stub cuts leave protruding stubs that allow disease and insects to take root because the branch collar can’t grow over it. If you can hang something off your stub, it’s too long. This can lead to backwards decay through the dead branch into the trunk.
Pro Tip: Avoid stub cuts by checking the length before cutting.
Heading cuts, or cuts that take off the end of a branch at a random point, damage the tree by stimulating it to grow many weak branches at the cut end. These small, weak branches don’t follow natural branch growth and branches can grow from unstable areas on the tree, risking breakage. This can also lead to pests and disease.
If you see trees with thin, patchy canopies, visible interior branches, and foliage is only growing at the ends of the branches, this is referred to as “lion tailing” and is the result of poor pruning. This compromises tree structure, leaves the tree vulnerable to weather damage, and increases the tree’s stress response. This can lead to growth sprouts, also called water sprouts, on the tree, a telltale sign of over-pruning.
Pro Tip: Avoid lion tailing by keeping growth even throughout the tree.
If a tree has already been liontailed, prune back branch ends slowly to allow interior branch growth. Once these grow, the interior branches will need to be pruned to spread the tree’s resources throughout the branches. This will need to be done in phases to allow the tree time to heal. You risk killing the tree if you remove all the ends at once after liontailing.
Tree topping is cutting the main trunk, also called the branch leader, at a random point below the apex to shorten the tree. The branch leader is one of the most important parts of a tree – it started as a sprout, grew all the branches, and developed into the tree you see today.
When a tree is topped, it develops weak, frail branches that sprout in groups along the ends of main branches as a stress response. These look unseemly, point to poor tree health, and fall off easily, causing debris. Once a tree is topped, it also requires more corrective work, as the small branches need to be cut to maintain size and appearance.
Pro Tip: Choose a lateral branch along the trunk and make a proper pruning cut just above it. If you cut successfully, this lateral branch will grow upward, becoming the new branch leader. Ensure you check what works best for the tree’s species before pruning this way.
PRUNING TOO MUCH
If you prune branches with diameter over 3 or 4 inches, the wounds will be too large for the tree to seal properly. Consider removing a large diameter branch by cutting it back to the trunk, so the branch collar can heal the wound. This will depend on the tree’s crown and branch structure.
If your customers haven’t pruned in a while, it may be tempting to remove much of the tree’s crown all at once, but this can be detrimental. Pruning, no matter how small the cut, still causes stress, so be sure to create a pruning plan and consider the tree’s age, health, and requirements before beginning. No more than 5% to 20% of a tree’s crown should be removed at one time to avoid tree topping. As mentioned before, these spindly branches cause more pruning in the future and the unwanted growth drains the tree’s energy reserves, reducing photosynthesis. Over-pruning will also allow fungi to easily enter the tree.
Good trees can’t be replaced overnight, and bark damage to trees can be serious or even fatal to the tree. Avoid bark damage from pruning by following best practices and not dropping pruned branches through the tree’s crown. Only use clean, sharpened tools; dull tools can create rough, imprecise cuts that rip the bark and cause more damage.
Safety While Pruning
The larger the branch, the higher the safety risk- in climbing, cutting, and falling branches. Heavier branches fall easier and are harder to dispose of. Ensure you and your crew have all safety measures in place and insurance.
Use the following safety procedures while pruning:
- Ensure your tripod ladder is set up correctly and securely.
- Make the first cut shallow, one or two inches away from the branch collar. The cut should be on the underside of the branch to prevent tearing bark.
- Make a second cut farther out along the branch than needed to remove excess branch weight. This will leave a stub about two to four inches from the branch collar.
- Make the last cut just beyond the branch collar to ensure a good pruning seal.
SiteOne Nurseries Can Help
If you have any questions or need supplies for the job, any SiteOne associate will gladly help. You can also shop on SiteOne.com or in our mobile app.