TREE PRUNING WINTER 2017
The Village’s tree pruning program is scheduled to begin in January. The area of the Village that will be pruned this cycle is encompassed by Garfield Street on the west, Columbia Avenue on the east, Chicago Avenue on the north and 55th Street on the south. Forestry staff estimates over 1,000 public trees will be pruned this winter. Detail on the program is below; residents are encouraged to contact the Forestry Program at 630-789-7043 or firstname.lastname@example.org with any questions or concerns.
The purpose of tree pruning is to improve tree structure, enhance vigor, and maintain safe conditions for all motorists and pedestrians as they move through the street corridor. Within the urban forestry profession, documented studies have shown that a five-year pruning cycle is ideal to maintain tree condition and value, and is more cost effective for a community to maintain. Therefore, the Village uses section pruning on a five-year rotation.
The benefits of an established tree pruning program on a regular cycle include:
- Enhancement of tree condition and shape
- Preservation of tree value
- Reduction in service request calls
- Reduction in number or severity of storm related damages
- Reduction in power line clearance related interference
- Reduction in the number of trees which undergo drastic changes in their appearance from before to after pruning
- Reduction in pruning cost due to less work required on each tree and less wood waste generated
During their life span, parkway trees should receive two general types of pruning: training and maintenance. Training is done primarily to develop a branching habit that ensures structural strength and adequate clearance once the tree is mature. Maintenance pruning is done on older and mature trees to remove hazards and improve vigor and aesthetics. Most trees in Hinsdale are mature; therefore, the bulk of the pruning workload is maintenance.
If training pruning is started early, structural tree problems can be corrected before they become too prominent. Large limbs removed at a later stage in the tree’s life not only dramatically change the appearance of the tree, but the resulting wounds are larger. Large pruning wounds are more likely to develop decay before the tree can completely grow over and close the wound areas. Also the systematic removal of low limbs as the tree grows in size allows the tree to channel more resources into developing a more upward crown. With a legal vehicle height limit of 13.5 feet (see Illinois Motor Vehicle Code 15-104), the forestry program has set this height as a target clearance over most streets and sidewalks. Depending on the growth habit of the tree species, some trees may require the removal of lateral branches from the trunk at heights greater than 13.5 feet to maintain a crown with adequate clearance. For example, trees with pendulous branches, such as Silver Maple, will have branches pruned up higher along their trunks than trees with more upright growth such as Sugar Maple. Once the main branches from the crown form a pleasing shape and are at a height which gives adequate clearance, pruning needs switch from training to maintenance, and the tree canopy can continue to develop in height and spread.
All pruning practices follow the standards presented in the ISA Tree Pruning Guidelines and in the ANSI A300 Standard. Pruning of all trees shall:
- Maintain the crown shape and symmetry typical of the species
- Improve the appearance of the tree
- Encourage upward growth for adequate clearance over streets, sidewalks, and other structures
- Remove dead, dying, diseased, interfering, and weak branches
- Remove trunk suckers and water sprouts which do not add to the shape of the tree
Tree Pruning – Frequently Asked Questions
Why Prune Trees?
Preventative tree pruning is designed to keep healthy trees healthy, and reduce problems in trees under stress. Dead, weak or hazardous branches and limbs are removed first, and then the remaining tree canopy is thinned as needed to improve branch spacing and maintain the symmetrical appearance of the tree. Lastly, lower tree branches may need to be removed or raised to provide safe passage for pedestrians and vehicle traffic, including emergency vehicles, plow and garbage trucks.
Where Does The Tree Pruning Occur?
The Village is divided into sections; the parkway trees in these sections are scheduled for pruning on a five-year cycle. Other pruning may be needed in order to repair damage from storms, construction injury, or as requested by residents.
Will I See A Big Change In My Parkway Tree?
Maybe. Most large mature trees in the Village have been pruned over several cycles. In these trees, only dead, weak, and hazardous branches will be removed; the overall shape of the trees will be minimally affected. Medium and smaller sized trees may need to be raised or thinned, so the difference will seem more severe. These changes are more apparent in the winter months; when the trees leaf out in the spring and add additional growth, the visual impact of pruning will decrease. The overall goal of promoting a safe, healthy and aesthetically attractive urban forest is the same for all trees.
Why Prune In The Winter?
Every pruning cut creates a wound. Shade trees are dormant in winter, which means there is low metabolic activity; pruning at this time will limit stress to the tree. Pruning will be completed before spring flush and growth occur to allow the trees to use the first surge of energy towards wound closure and new growth. Trees expend a considerable amount of energy in creating and maintaining leaves; dormant season pruning avoids removing this leaf investment. Finally, the environmental pressure to trees is moderate in winter. Trees are not overcoming stress from high temperatures, drought, or insect and disease pests.