Street Tree Pruning

1. Health -
   to remove deadwood and branches affected by disease or insects
2. Structure -
   to remove weakly attached and broken branches, as well as branches that conflict with each other
3. Safety -
   to provide sidewalk and street clearance for pedestrians and motorists, to eliminate traffic sight obstructions, to prevent damage to street trees caused by trucks clipping branches as they pass under them, and to keep trees clear of traffic signals, street lights, etc.
4. Trimming Cycle -
   with over 127,000 trees to take care of, it can be a long time before a Forestry crew can return to prune a tree again. With limited staff and funding, the time between tree pruning's may be up to 11 years. That means arborists may have to cut enough to keep branches at a safe height, not just for now, but for the next 11 years
5. Future Growth -
   since the Forestry Section may not be able to return for up to 11 years to prune a tree again, it is necessary to plan for the future by removing branches now to promote growth which will not conflict with the site and to make smaller pruning cuts now instead of larger ones later

Removing Temporary Branches

• Branches do NOT change their position on the trunk as the tree grows.
• All branches on trees with less than about 4" caliper will eventually be removed- temporary branches first 10 years.
• Temporary branches need to be removed when small to prevent large pruning cuts that can cause wood-decay.
• One main stem will be selected as the leader and branches competing with it need to be reduced or removed.

Figure 10 All existing branches on these recently planted trees along a street will eventually
have to be removed in order to provide clearance for buses, garbage trucks, and tractor trailers.