Why Prune Our Trees?

Why Prune Our Trees?

Marianne C. Ophardt
Washington State University Cooperative Extension
Area Extension Agent

If someone knocks on your door and tells you you're trees needs pruning, beware!  This person may be a qualified arborist looking for work or they simply may be a chainsaw owner looking for some good firewood.  First let's examine the reasons why a tree might need pruning.

Dead limbs or branches with a core of decayed wood are hazardous. They should be removed whenever they become evident.  Also, broken limbs and branches should be properly pruned as soon as possible after the damage has occurred.

Limbs and branches that interfere with utility wires, gutters, roofs, and chimneys should be removed.  Branches that create a safety hazard by obstructing a view of the street or sidewalk should be removed using proper pruning techniques.  Branches that intersect and rub should be pruned to eliminate the problem.

Tree pruning is sometimes employed to lessen crown density in order to reduce wind resistance, to shape the tree, or to allow for greater light penetration. Beware if someone says your tree needs pruning because it's "too big."  Keep in mind that healthy trees with adequate root systems seldom "NEED" pruning just because they are big.  That just isn't true. 

In some cases, tree removal may be a better option than pruning.  Trees warrant removal if they are obviously dead or dying.  Trees definitely should be removed if they pose a serious hazard because of internal decay or the destruction of a large portion of their anchoring roots.  If pruning can't remedy the situation, trees growing too close to a building or crowding other trees should be removed.

Good landscaping can add 15 to 20 per cent to the value of your home.  Healthy, attractive trees are an asset to your landscape's design.  Unhealthy, poorly pruned trees are a liability.  When you hire someone to prune your tree or to help you decide on removal, you should look for a qualified, trained certified arborist, not just anyone who knocks on your door.