NOTE: Please do not prune street trees in Palo Alto as the City ordinance prohibits residents from pruning street trees. Also note that the guidelines below apply to most trees; however, exceptions may include fruit trees, multi-stemmed trees, and palms.
Cost: Which tree is more likely to become costly to maintain? A or B?
Safety: Which tree is more likely to become a safety hazard? A or B?
Longevity: Which tree is more likely to live a shorter life? A or B?
The correct answer is Tree B: it will be more costly to maintain, more of a safety hazard, and will likely have a shorter life.
What’s the difference between happy Tree A and unhappy Tree B? Tree A was pruned at a young age to have a central leader (central trunk), while Tree B was not.
A tree without a central leader is less structurally sound, and more likely to need costly and unsightly pruning as it matures, as in Figure 1 below. Trees lacking a strong structure are also vulnerable to serious limb breakages during a storm, as in Figure 2 below.
Figure 1: Mature tree with unsightly cuts:
Without proper pruning as a young tree, a mature tree may require unsightly and costly cuts.
Establishing good structure early in this tree’s life would have saved time, effort, maintenance costs, and prevented an eyesore!
Figure 2: Mature tree with storm damage:
In urban areas, large limb failure poses a public safety hazard, puts property at risk, and results in the unnecessary loss of mature trees.
As renowned arboriculturalist Larry Costello, PhD, said repeatedly in his Canopy young tree pruning workshop for landscape professionals, “What a waste!”
To prevent these and other problems, learn the five-step method used by Dr. Costello, Canopy, and others to properly prune young trees. (See video above.)