Tree Health Care
Diagnosis first. Treatment only when it's justified.
A tree that looks sick may be dealing with an insect, a disease, drought, root damage, or all of these at once. Spraying or injecting it without knowing the cause wastes money, and sometimes it does harm. My plant health care starts with a careful diagnosis on site. Then I recommend the least invasive treatment that will actually work.
I'm Matt Allen, an ISA Board Certified Master Arborist with about 30 years in Portland-area tree care. I'm also an Oregon Department of Agriculture licensed pesticide applicator, so I can diagnose the problem and apply soil and trunk injections myself. You won't be handed off to a spray crew.
How plant health care works
Assessment. I inspect the tree's canopy, trunk, root flare, and soil. I look for insects, disease signs, and stress factors such as compaction, grade changes, or drought.
Diagnosis. I identify what's actually wrong. That may include a lab sample when the cause isn't clear on site.
A written plan. You get clear recommendations, in order of priority. That can include cultural care such as mulching, watering, or soil work, targeted treatment, monitoring, or, when it's the honest answer, removal and replanting.
Treatment. When treatment is warranted, I use targeted soil or trunk injections. They put the product inside the tree, where the pest is, instead of drifting across your yard.
Follow-up. Many problems need monitoring over a season or two. I'll tell you what to watch for and when I should come back.
Common tree problems in the Portland area
Our trees face a mix of native pests, newly arrived invaders, and stress from hotter, drier summers. These are the problems I see most often in Lake Oswego, Beaverton, and SW Portland:
Emerald ash borer. It's an invasive beetle that kills nearly every untreated ash tree it reaches, and it's now in the Portland metro area. Healthy ash trees can be protected if treatment starts in time. Emerald ash borer
Western redcedar dieback. Cedars are browning and dying from the top down after recent heat and drought. (Page coming soon)
Douglas-fir decline. This covers root rots, needle cast diseases, and bark beetles that attack stressed firs. (Page coming soon)
Bronze birch borer. It causes birch trees to die back from the top. (Page coming soon)
Mediterranean oak borer. It's a new invasive beetle attacking Oregon white oaks in the metro area. (Page coming soon)
Aphids, scale, and sooty mold. These are behind the sticky residue on cars, patios, and plants under lindens, maples, and birches. (Page coming soon)
Anthracnose and Verticillium wilt. These leaf and branch diseases hit dogwoods, sycamores, and maples. (Page coming soon)
When to call an arborist
Call for an assessment if you notice any of these:
Thinning or yellowing in the upper canopy
Branches dying back from the tips or the top
Small holes, cracks, or sawdust-like material on the trunk
Sticky leaves or a black coating on leaves and surfaces below the tree
Mushrooms or conks at the base of the tree
Sudden browning of needles on a conifer
Many treatments only work while the tree still has enough healthy canopy to move the product. Early diagnosis gives you the most options and usually costs the least.
Serving Lake Oswego, Beaverton, West Linn, Tigard, and SW Portland, plus the wider Portland metro area.
