Why prune?

Landscape trees grow differently than forest trees, this is why landscape trees require pruning whereas forest grown trees do not. Trees in the forest compete with one another for light, so they grow tall and skinny as they reach skyward for the sunlight. With landscape trees, the opposite is true, landscape trees have space to grow, lots of available sunlight and tend to branch excessively and spread outwards. Landscape trees produce long horizontal limbs that become too heavy and can snap off. Landscape trees also grow crisscrossing limbs that rub against each other and promote disease. This is why landscape trees require pruning.

Landscape trees are close to our houses, fences and common areas. We want them to be safe to be around, this is why pruning is so important. An added benefit of pruning is that it helps make our trees beautiful and healthy for the long-term.

The definition of pruning is to remove a part of a tree. This simple definition, because proper pruning is very detailed and specific to the needs of a tree. The type of pruning a tree requires depends on the tree species, age, size, branch structure and location of the tree.

Pruning for Structure

Pruning while young is the easiest way to set up your tree for success, pruning young trees allows for the branch structure and shape of the tree to be decided at an early age. Trees can be pruned for strength and ability to hold up against snow and wind. Leading branches or “leaders” are the large structural branches that support large parts of the tree. Forest trees most often only have one leader, whereas landscape trees have many leaders. Competing leaders should be removed or shortened to allow one leader to become dominant (just like a forest-grown tree). This can drastically reduce the chance of the tree splitting at a union where two limbs of equal size originate.

Crisscrossing branches can rub on each other which weakens the branches and promotes disease. This often means removing the crisscrossing branches. The main structural branches are by far the most important part of the tree, so any branches that interfere should be removed. Numerous smaller cuts are often better than one to two larger cuts at the trunk. These smaller cuts seal over faster with less chance of long-term decay setting in - yet another reason to prune while trees are young with smaller branches.

Pruning for Disease Control

Pruning creates better air flow through the canopy and lets more sunlight pass through the tree. This slows or prevents the spread of fungal disease and prevent moss from growing on the trees bark. If a tree is already suffering from fungal disease then pruning off the affected branches can help slow or stop the spread.

Pruning for Safety

Dead branches are a safety hazard to the area below the tree. Damaged branches from a previous storm or strong wind can fail at a moments notice. Long branches are heavy and may break off in the wind.

When to prune

Small trees should be pruned every 2-3 years to create a good long-term structure for the tree. Mid sized trees should be pruned every 3-5 years. Mature trees and large trees should be pruned every 5-7 years but when they are pruned it is important it is a thorough pruning.