WHY TREES ARE PRUNED  Trees naturally shed limbs. Branches that are weak or impede growth tend to die and fall from the tree. Pruning mimics that natural process. Periodic pruning of City owned trees removes potentially hazardous limbs, promotes tree health and provides clearance over streets, sidewalks and permanent structures. (Limbs must clear structures by 10 feet, sidewalks by 12 feet and streets by 14 1/2 feet). City Forestry standards and techniques can also be applied to trees on your property.
TYPES OF PRUNING The type of pruning called for depends on a tree's age and health as well as the service being delivered. 1. TRAIN PRUNE- Young trees planted within the last 7 years grow quickly and densely. Removing low limbs, crisscrossing limbs, multiple main stems and limbs with weak branch attachments can avoid problems later (like obstructed sidewalks and streets). 2. HAZARD PRUNE- A minor pruning which includes removing dead, decaying, hazardous and low limbs. 3. MAINTENANCE PRUNE- Includes hazard pruning and removal of limbs that cross, have weak attachments and thinning of dense growth to allow sunlight and wind through the tree crown, which promotes health and sound structure.
VISUAL AND OTHER PRUNING CONSIDERATIONS Tree Health - A tree's health should be considered prior to pruning. A hazard prune is most appropriate for a tree in poor health. No more than one-third of a tree's live crown should be removed in one pruning. Aesthetics - The natural crown shapes of different tree species are always considered in pruning, but trees are not pruned to provide a particular shape. Limbs are removed for functional reasons only. Visual Impacts of Pruning - The visual "voids" in a tree crown or along a streetscape that follow pruning (especially after low limbs are removed) occur while one's mind adjusts from memory of its former appearance. This will fade after the growing season, and in the longer term, helps protect our trees' health. FORESTRY DIVISION PRUNING SERVICES
Forestry takes care of street trees (located between the sidewalk & curb) and park trees. Pruning of City owned trees is completed using the following methods: 1. SERVICE REQUESTS - An inspection confirms that problems reported by residents involve hazardous conditions or property damage. This least efficient approach is used only when unavoidable. 2. PRIORITY PRUNING - An annual survey identifies trees presenting problems. Crews follow up in the fall or spring by "hazard" pruning specific trees or all those on streets where needed. 3. SYSTEMATIC PRUNING - Maintenance pruning is scheduled for every tree on streets within an area, usually in summer or winter. Smaller trees requiring less resources are often pruned separately. Call Forestry at 428-7581 if you need your city owned tree inspected. We'll assess its condition. Hours: 8 a.m. - 4 p.m., Monday - Friday
TIPS FOR PRUNING TREES ON YOUR OWN PROPERTY Pruning Tools
Always use sharp pruning tools appropriate to your job (i.e., using a chainsaw for pruning too small a limb may damage the tree). Follow all maintenance instructions, be careful and, remember, pruning tools cut flesh easier than wood. Hand Pruners
These come in various types and should be used for pruning limbs 1/2 inch in diameter or less. Hand Saws
Most cut on either the push or the pull strokes and should be used when pruning limbs larger than 1/2 inch in diameter or less. Pole Saws
These are pull stroke saws on wood or fiberglass poles of various lengths to allow pruning higher limbs. Be sure to stand out of the way of falling limbs while using and not to operate near overhead electric or other utility lines. Pole Pruners or Clips
Scissors-like pruning tools to reach higher small limbs, these clippers are operated by a rope attached to fiberglass or wood poles (simular to pole saws). Follow the same safety rules that apply to pole saws. Chainsaws
Available in various sizes for removing large diameter limbs, chainsaws are very dangerous and should be used only after training. Proper Pruning Cuts
The following techniques should be applied when pruning
all woody plants. Generally use the three-step method illustrated for pruning a limb. 1. Make the cut on the underside of the limb, away from the trunk or parent limb (to avoid ripping). 2. Make a cut on the top side of the limb (outside the bottom cut) to remove the majority of the limb. 3. When removing the remaining portion, do not make the final cut flush with the trunk or main limb; cut at the branch collar.
Removing Whole Limbs vs. Pruning the Tips
In most cases, it's best to remove a whole limb at the trunk rather than cut off just an end unless a limb is growing into the side of a permanent structure. Cutting off the end creates wounds which do not readily close and may require pruning
again soon. Pruning Flowering Trees & Shrubs
All plants have flowers, some are just flashier than others. Prune immediately after flowering. Flower buds are set in the spring or fall after flowering. Pruning just before flowering removes the flower buds. Pruning Shade Trees
Avoid pruning in the fall and spring to keep from placing undue stress on trees during leaf out and leaf drop periods. If you must, just prune minimally (hazard prune). Hiring An Arborist
Select a qualified member of a professional organization. Ask for (and check) references. Make sure they can document workers compensation and damage insurance coverage. Get three quotes. (Better prices are available in the winter.)
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