By Mason Wordell, Urban Forestry Tree Plan Coordinator and AmeriCorps Member
Join Urban Forestry and the Albina Neighborhood Tree Team (ANTT)
for a pruning workshop and work party!
When: 8:30-12:00pm January 7th, 2017
Where: Sons of Haiti Masonic Lodge & Food Cart Pod | N Mississippi Ave. & NE Fremont St.
8:30 – 9:00 am – Sign-in, coffee & bagels
9:00 – 9:45 am – Pruning Demonstration
10:00 – 11:45 am – Pruning neighborhood trees in small groups
11:45 – 12:00pm – Return and wrap up.
Portland Urban Forestry and ANTT are partnering to offer this street tree pruning workshop to improve tree health and walkability in the area. Pruning is an important part of tree care and maintenance, and everyone is welcome to participate in this workshop to learn more about how they can actively care for their trees. Knowing when to prune and what to look for can help you make successful cuts that will help cultivate beautiful, structurally sound, and long living trees.
When we plant a tree, we hope that it will grow tall and straight; that it will have a full, healthy crown with strong, well-spaced branches; that it will cast a broad expanse of sheltering shade; that it will resist damage by wind and ice; and that it will be easy to maintain. Without proper pruning, however, a tree can become unhealthy and expensive to maintain. An unmaintained or poorly maintained tree is more likely to become hazardous, with branches that break during storms, have weak and unsightly shoots, and interfere with traffic, pedestrians and overhead wires. To ensure that Portland’s urban forest continues to enhance our daily lives, we must properly care for the young trees we plant.
If you are ever interested in pruning your street tree, your first step is to secure a free pruning permit from Urban Forestry. Depending on the kind of pruning you need to do, you can either decide to prune the tree yourself or hire an arborist. Urban Forestry has a list of tree care professionals that can help you if you have a large, mature tree in need of pruning. At our workshop, we’ll cover the basics of how to prune young trees. Listed below are several goals to keep in mind when you are considering pruning a street tree.
1. Young tree pruning - Young trees should be pruned to develop good structure, including a strong and well established central leader, strong branch attachments, and adequate spacing and distribution of scaffold branches. While there are several types of trees that do not have one leader, many street trees have once central leader (or stem). Removing or reducing co-dominate branches encourages a strong leader, which is important for tree structure. Trees with large, co-dominate leaders are more likely to fail or split during stormy weather or heavy snow fall. Young tree pruning will need to occur on an ongoing basis over the first ten years after tree planting.
Letters indicate the following kinds of cuts for a tree 3-4 years after planting. A: Remove branches that are heading back into the tree. B: Remove branches that are rubbing. C: Eliminate branches with narrow angles. D: Remove suckers from around the base of the trees whenever they emerge. Image courtesy of Urban Forestry.
2. Crown Cleaning - The removal of water sprouts, and dead, dying, diseased, crowded, weakly attached, and low vigor branches from the tree’s crown. A sucker is a shoot which grows from a bud at the base of a tree or from its roots. Pruning suckers or ‘water sprouts’ early will help keep the base of the tree clear for pedestrians, and also reduce the energy that a tree is putting into unnecessary growth. . Removing dead, dying, or diseased branches can prevent rot or insects from entering the tree and damaging the tree tissue. In addition, removing dead or dying branches can reduce the hazard of falling branches during stormy weather. You can prune these branches anytime in the year without fear of harming the tree.
3. Crown Raising – the removal of lower branches of a tree in order to provide clearance for vehicles, pedestrians, and buildings. Street trees are subject to codes that regulate how low a branch can be. Branches must be at least 7 ½ feet high off the ground when above the sidewalk, 11 feet high on residential streets, and 14 feet above main arterial streets. Pruning these branches helps create safe clearance and visibility for all pedestrians and drivers.
Branches must be at least 7 ½ feet high off the ground when above the sidewalk, 11 feet high on residential streets, and 14 feet above main arterial streets. Images courtesy of Urban Forestry.
4. Crown restoration - used to improve the structure, form, and appearance of trees that have sprouted vigorously after being broken, topped, or severely pruned using heading cuts. Crown restoration may require several prunings over a number of years as new dominant branches take time to form.
You never want to remove more than 25% of a tree’s crown during a single pruning session. Removing any more can damage a tree permanently, and severely slow its growth. In general, it is best to prune trees in the winter, and encourages vigorous growth in the spring. Pruning during the spring and summer removes leaves that produce food and energy for the tree, and can slow tree growth.
If you find this interesting, I encourage you to start the New Year right and join the Albina Neighborhood Tree Team (ANTT) and Urban Forestry for the first pruning workshop of the year! Make a difference in your neighborhood and connect with tree lovers during this informative and fun workshop.
Certified Arborists can receive 3 hours of ISA CEUs for participating and leading small groups. Contact firstname.lastname@example.org for details!
View the City’s official pruning standards.
For more information, or if you have something you want to talk about, contact:
Tree Plan Coordinator and AmeriCorps member