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City of Lake Oswego Oregon - Luscher Farm

Tree Care and Maintenance Archive

City of Lake Oswego Oregon Official Website

Summer, 2017

Trees and turfgrasses are commonly planted together in residential landscapes, but are not so easily compatible. They compete for water, sunlight, nutrients, and root space. Tree trunks are easily damaged by lawnmowers. And, what about those expansive surface roots damaging your lawnmower blades?

Understanding how to better manage the competition will help you take advantage of the variety of benefits trees and turfgrasses can provide. For example: surface rooting throughout lawn areas can be prevented with proper tree species selection, soil improvements, and providing a slow, deep, and infrequent watering beneath tree canopies; a grass-free ring of bark mulch is a good alternative around tree trunks to help keep lawnmowers away, in addition to a variety of other benefits the mulch will provide; and, new varieties of shade tolerant grasses are becoming more available.

Learn more about trees and turfgrasses by visiting these sites:

Trees and Turf Brochure (TreesAreGood.org Tree Owner Information)
Tree roots coming to the lawn surface can be a real headache (Seattle Times, Ciscoe Morris, October 29, 2015)
Mechanical Damage to Trees: Mowing and Maintenance Equipment (Purdue Extension, FNR-492-W)
Tree Watering (Arbor Day Foundation)
Plant Guide: Water-Efficient Plants for the Willamette Valley

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Spring, 2017

English ivy is the most common invasive plant in Lake Oswego. It is an aggressive species with no natural enemies that grows and reproduces quickly, outcompetes native plants like wildflowers and ferns, and has vines that commonly grow up tree trunks with detrimental effects. English ivy competes with trees for water and nutrients, deprives tree bark of normal contact with air and microorganisms, and increases susceptibility to wind stress and the risk of canopy or whole tree failure.

Property owners can remove ivy from trees by cutting the vines at chest height in a ring around the trunk with pruners, loppers or saws. Pull the lower portion of the cut vine off of the tree trunk carefully to avoid bark injury, and pull or dig out the attached roots. Clear a 3- to 5-foot ring around the base of the tree to help prevent or postpone re-growth up the trunk. The upper portion of the vines can be left on the tree because it will die back.

Learn more about the detrimental effects of English ivy and how to remove it by visiting these sites:

Factsheet: Ivy Removal in a Home Landscape

Video: How to Remove Ivy

Explore: The Ivy Files

 

Seasonal Tree Care Tips: Preparing Trees for Fall and Winter

Fall is a great time to be prepare your trees for the winter weather ahead. With leaves falling from trees, branch structure and defects are easier to see, so it’s a great time of year to have your trees inspected by an ISA Certified Arborist. Branches may need to be pruned, cabled or braced to help prevent storm damage. Fall is also a great time of year to mulch and fertilize. Mulch helps to insulate the soil and retain moisture, but too much mulch can be harmful. Generally, a 3” deep ring of mulch in a 4’ circle around your tree is sufficient, but don’t pile mulch against the tree trunk. Fertilizer should never be applied without first obtaining a soil test to check for nutrient deficiencies.

Visit these sites to learn more about preparing your trees for winter:

Cabling & Bracing Trees as a Corrective Measure

Mulching Trees & Shrubs

A Guide to Collecting Soil Samples

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FALL, 2016

Trees provide desirable benefits in the landscape, but may become hazardous when they have defects resulting in increased failure potential and are located within striking distance of targets—such as people, vehicles, buildings, or other infrastructure—that could be injured or damaged by tree failure. Reasonably assessing the potential risk of injury or damage that a tree may cause and managing to reduce risk is called Tree Risk Assessment. The Tree Risk Assessment Process involves a systematic evaluation of an individual tree along with review of site use, and is a specialized area of expertise that should be undertaken by a trained professional. An ISA Tree Risk Assessor Qualified Arborist can assign a hazard risk rating to your tree and provide management recommendations to reduce risk, such as relocating potential targets, pruning to remove defective parts, or whole tree removal. It is a property owner’s responsibility to ensure that their trees are reasonably safe and to manage their trees in order to reduce risk. Visit these sites for tips on recognizing tree risk and know when to contact a professional: