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Archive for the ‘Pests’ Category

Buying A Home? Don’t Forget To Inspect The Trees!

Wednesday, January 17th, 2018


Shrewd house hunters always await a professional inspection before purchasing a home. Too often, though, homebuyers completely neglect to inspect the trees surrounding the house and property.

It’s always a good idea to hire an ISA Certified Arborist before buying a house. A yard may require extensive tree maintenance or have other tree issues you’ll need to take care of. Partnering with an Oregon and Washington arborist will help you avoid unexpected surprises down the road.



Why Inspect Your Trees?

Inspecting the trees in a yard before purchasing a house ensures the property aligns with all local landscaping regulations. A professional and certified Washington and Oregon arborist knows what to look for and will help ensure you make a fully informed decision.

Beyond regulations, the most important reason for a pre-purchase home and property tree inspection is safety. Problematic trees pose a great risk of damaging your property or endangering your family.



Tree Issues to Watch for When Purchasing a Home

Your realtor or home inspector may not understand how to spot signs of a problematic tree. An ISA Certified Arborist, on the other hand, will know exactly what to look for. They will ensure you are fully informed as you make the big decision to buy a home in Oregon or Washington.

Here are a few of the things an ISA Certified Arborist will look for when inspecting a house and property.

Tree Species

Beyond potential tree dangers or issues, it’s smart to know the species of trees you’ll be dealing with. Here in Washington and Oregon, there are over 60 native tree species alone!

Arborists will begin by determining the type of trees on the property. Then, they’ll educate you on what to expect, including:

  • Seasonal characteristics of the trees
  • Maintenance requirements
  • Common issues

Whether or not you have any interest in trees, knowing the species surrounding your property is very important for maintaining your new house and yard.



Dead, Dying, or Diseased Trees

Dead, dying, or diseased trees on your property don’t just look bad, they are also a huge inconvenience and potentially catastrophic. Dead or dying trees attract pests and can fall without warning. Diseased or pest infected trees can spread to other trees around your property.

A dead or dying tree on your property can’t fix itself. It will be your job as the new homeowner to take care of the issue. This can be an expensive undertaking, especially if it’s a large tree and requires removal.
There are 3 tell-tale signs an Arborist will look for to determine the health of your tree:

  1. Trunk Damage: As a tree ages, old bark will fall off and grow a new layer. A tree without bark can be an indication of failing health. An Arborist will also look for vertical cracks and damage along the tree trunk.
  2. Fungus: Fungus along the trunk or branches of a tree may indicate internal rot. A rotting tree means it’s either dying or already dead.
  3. Damaged Roots: Some signals an Arborist will look for are small branches popping up from the base of the tree trunk. This is known as epicormic shoots and means the tree is under extreme stress. Another sign of damaged roots can be a tree leaning to one side.



Trees Too Close to the House

At a glance, a big maple tree in the front yard adds character to the property. But if the tree isn’t sturdy, there’s a chance it could come crashing down on your house during a storm. A tree decades old can have hidden problems that the current owner isn’t aware of.

Even if the tree is sturdy and safe, an Arborist can analyze the amount of yearly maintenance will be required.

Here some questions an Arborist can help you answer:

  • Will regular pruning be required?
  • Will you be dealing with an abundance of leaves to clean during the fall?
  • Is the tree close enough to drop branches or debris into your gutter?
  • Does the tree have nuts or fruit you’ll need to take care of?

A tree may not be very close to your house, but if it’s big enough, its branches may pose an issue. Unruly tree branches can fall on your roof or car, crash through windows, or deposit debris around your yard.



Roots Disturbing the House Foundation

A beautiful tree in your yard could be causing a significant threat to the foundation of your home.
Roots grow in search of water and nutrients. Depending on the type of soil surrounding your house, this can cause structural damage to your property.

For instance, if your house sits on compact clay soil, roots pushing their way though can affect the placement of this soil. This can cause your foundation to shift and crack.

Another type of soil that is easily damaged by roots is loose dirt and rock. This material will easily shift and become displaced as roots move through.

ISA Certified Arborists can get a read on the type of soil around your property. They will give you an idea of how roots are affecting your foundation, or how they may cause problems down the road.



Problematic Tree Pests

Perhaps the most annoying tree issue to be aware of is a pest infestation. Depending on the Pacific Northwest area you live in, there are certain tree pests to be aware of. An Arborist will tell you exactly what type of insects to watch out for and whether or not a tree is currently infected.

A pest-infected tree can pose many problems. Some bugs can chew through the wood and bark of your tree, making it unsound and unsafe. Others will eat away at your tree, slowly killing it. If you’re dealing with a serious infestation, it’s possible the bugs have spread to other trees on the property.

Beyond insects and pests, it’s also smart to be aware of other critters than may be living in your trees. From squirrels and raccoons to bees, owls, and other birds.



What If the Tree Inspection Reveals a Problem?

A tree issue on the property doesn’t always mean you shouldn’t purchase the house. But it should play a role in your decision. If the house or property has a severe tree issue, it could cost you hundreds (and even thousands) of dollars. You may be able to negotiate a lower price on the home or have the seller pay for the cost of maintenance.

If you’re looking at a home in the Oregon or Washington area, contact us. We’ll ensure you’re getting the best deal for your money and eliminate unwanted surprises by conducting a pre-purchase home and property tree inspection. Our ISA Certified Arborists are happy to help you.


Category Landscaping, Pests, Roots, Tree

12 of the Amazing Animals That Live in Portland’s Trees

Tuesday, September 27th, 2016

Fascinating Animals in Portland TreesRecently, we talked about some of Portland’s most notable heritage trees. In this month’s post, we’ll still be talking about trees, but this time around we’ll take a closer look at a few of the fascinating animals that call Portland’s trees home!


So many different species of birds live in Portland area trees! Here are a few of the most common:

House Finch

House Finch in a Tree

The House Finch is a small bird– about the size of a person’s hand. Males of the species have a red forehead, throat, and chest while females are recognizable for their rusty brown color.

House Finches are found all over the Portland area, but they tend to avoid dense forests. You’ll find them downtown and in the suburbs, too! Interestingly, House Finches didn’t get introduced to the Willamette Valley area until the 1940’s, but clearly they’ve thrived!

Western Scrub-Jay

Western Scrub Jay

The Western Scrub-Jay is a big bird, usually measuring about a foot long. It’s found throughout the Portland area and often nests in oak trees or other deciduous trees. The Scrub-Jay is actually kind of like a squirrel– it buries nuts and acorns to eat later!

Dark-Eyed Junco

Dark Eyed Junco Bird in Tree

This small bird is frequently spotted at Portland area birdfeeders. But when it comes time to nest they prefer pine, fir, and other coniferous trees. The easiest way to identify the Dark-Eyed Junco is by its jet black head and small sparrow-like body.

Rufous Hummingbird

Tiny Hummingbird

These tiny birds are just gorgeous! The male Rufous Hummingbird has iridescent green and orange red feathers. The females tend to be more subdued in color.

Hummingbirds feed on nectar and tree sap and build their tiny nests in all sorts of trees. The Rufous Hummingbird is very territorial so don’t be surprised if you get buzzed when you get too close!

Red-shafted Flicker

Red Shafted Flicker

The Red-shafted Flicker is a large woodpecker that lives in wooded areas throughout the city and surrounding areas. Even if you’ve never seen one, you probably recognize their Wocka-Wocka-Wocka birdcall.

American Robin

American Robin

The American Robin is very recognizable with its orange chest and grey body. You’ll see it throughout the city during all but the coldest months of the year when they head south.

White Crowned Sparrow

Sparrow in a Tree

Another one of Portland’s most common birds, the White Crowned Sparrow is a somewhat bulky bird with a brown and white mottled appearance. They love to eat seeds from birdfeeders and nest in shrubs and small trees! Unlike other birds, the White Crowned Sparrow resides in the Portland area year-round and generally doesn’t migrate south for the winter.

Owls, Hawks & Falcons

Big Owl

In addition to songbirds, there are also plenty of predatory birds in the Portland area, including Barred owls and several species of hawks and falcons. These predatory birds use their well-hidden nests for resting and rearing their young, so you’re more likely to see them flying in the open than perched in a tree. Check out local parks like Oaks Bottom, the Hoyt Arboretum, and Forest Park for your best shot at seeing a predatory bird in the wild!


In addition to a wide variety of birds, you’ll find other interesting creatures nesting and living in trees throughout the Portland area, including raccoons and squirrels.


Raccoons hide in trees!

While most people don’t think of raccoons as tree-dwelling animals, they’re up there! During the night, clever urban raccoons will climb trees to steal eggs from a bird’s nest for food. During the day, they may rest in a tree. Be careful of approaching any raccoon as they can be aggressive if they feel cornered!

Eastern Gray Squirrel & Eastern Fox Squirrel

Invasive Squirrel in Tree

Unfortunately, these two common species of squirrel are both non-native species and are considered invasive and damaging to native species. They’re normally found in areas with lots of people as they’ve learned to take advantage of food left by humans.

Western Gray Squirrel

Western Squirrel Loves a Nut!

The Western Gray Squirrel is a native species that is unfortunately on the decline due to removal of old growth forests and increasing numbers of non-native squirrel populations. The Western Gray has more pronounced black and white colored fur compared to the Eastern Gray. Western Gray Squirrels are considered a threatened species, so make sure you don’t disturb any that you see!

Bees & Wasps

Bees in Trees!

Bees and wasps aren’t as cute as hummingbirds or baby squirrels, but they frequently live in trees throughout the Portland area. When it comes to bees, you have nothing to worry about. During swarming season, it can be a little unnerving to see a giant mass of bees on a tree in your yard. However, bees “swarm” naturally as they outgrow their current nests and are just looking for a place to call home.

Just call the Bee Hotline at (503)444-8446, and an experienced beekeeper will come to your home and collect the bees and give them a new home.

If you see a wasp nest, however (or aren’t sure about what you’re seeing), keep your distance! Wasps and yellowjackets can be aggressive and their stings can be very painful (or even dangerous if you’re allergic). If you think you see a wasp or yellowjacket nest in a tree in your yard, the best thing to do is keep your distance call a professional exterminator to have it removed.

Do You Have Questions About Animals In Your Trees?

At Northwest Arbor Culture, we’re happy to come out and take a look at your trees. Just give us a call at (503)538-8733. We can tell you if a tree has been damaged by a nesting squirrel, if a bee or wasp nest needs to be removed, and answer any other questions about animals that might be living in your trees.

Photo Credits: Beau Considine, Oregon Dept. of Fish & Wildlife, John Flannery, Kathy & Sam, Darron Birgenheier, Lip Kee Yap, BTWG, Jessica Mullen, David Slater, Jean, Ingrid Taylar, Lars Plougmann

Category Pests, Tree

The 6 Most Common Causes of Tree Problems & Diseases

Tuesday, May 31st, 2016

Common causes of tree damage and disease

Did you know that there are some trees that can live to be over 5,000 years old? While the trees in your yard won’t live that long, if they’re well maintained, they can live for 50 years or even longer! Unfortunately, many trees become diseased, rotted, or damaged before they can reach their full potential.

Today we’ll talk about some of the most common causes of tree problems and diseases as well as signs that your tree might be unhealthy and in need of help.

Weather & Storms

Rainy Portland Weather

Our Portland climate is generally pretty mild, but our weather can still cause serious damage to trees. During the rainy months, too much precipitation can cause the ground to become waterlogged, loosening a tree’s roots. This can cause trees to lean or even topple over! During the winter, ice and snow accumulation can put stress on branches and cause them to break off

Root Damage & Loss

Tree Root Damage

Tree roots are like an anchor, holding the tree steady and straight. They also absorb water and nutrients from the soil. Without a healthy root system a tree simply can’t be healthy. Since they’re underground root problems are often difficult to spot until damage has already been done. Roots can be:

  • Cut or crushed by heavy construction equipment
  • Infected by invasive fungus
  • Damaged by lack of available nutrients or changes in the environment

Disease & Infection

Infected Tree Disease

Diseases and infections from fungi, bacteria and other sources can be deadly. In the Portland area, for example, elm trees are especially susceptible to Dutch Elm disease. Dutch Elm disease is caused by a fungus that’s carried by certain types of beetles. The disease can spread quickly and kill many trees if it’s not caught early. Other common tree diseases include:

  • Anthracnose – A fungal infection that attacks leaves, flowers, and fruits. You’ll often see this on dogwood trees.
  • Dothistroma – Another fungal infection that can kill younger pine trees. This infection causes a pine tree’s needles to fall off, preventing the tree from creating the energy it needs to grow.
  • Leaf Blight – Actually a variety of related ailments, leaf blight can damage a tree’s canopy, over time weakening and killing the entire tree.


In a way, trees are just like people. As they age, they become more susceptible to some diseases and ailments. The branches of older trees may weaken due to an accumulation of small cracks and breaks. Depending on the weather, older trees may dry out and become brittle and unhealthy.


Tree Damage from Construction Equipment

Heavy construction machinery can compress soil and damage a tree’s root system. It’s important to remember that a tree’s roots extend far from its base (in some cases 30 feet or more), making it important to stay well away from trees during construction. In addition, careless use of construction equipment can rip off a tree’s leaves and branches or cause damage to the trunk itself.

So be careful when you’re doing any work in your yard!

Poor Maintenance

Trees need our help to stay healthy! If you don’t take good care of your trees, they’re more likely to suffer from disease, damage, and other common tree problems. Luckily, most trees don’t require much maintenance. They only require regular trimmings and inspections to make sure the bark, roots, branches, and trunk are healthy and stable.

What To Look Out For

While some tree problems are tough to spot, there are some telltale signs you can be on the lookout for.

Sudden Changes to Leaf Color & Density

Changing Leaf Colors

If a tree’s leaves suddenly change from green to yellow, or if leaves become splotchy or have a “banded” appearance, that could be a sign of fungal infection or disease. Or if a tree’s leaves or needles begin to fall off out of season, that’s another warning sign.

Unusual Growths & Knots

Tree Fungus

Bulbous growths or swollen areas in a tree’s trunk can be caused by bacteria growth. Fungus growing from a tree’s trunk or branches can also be signs of an unhealthy tree. These growths are often signs that your tree isn’t getting the nutrients it needs to grow normally.

Insect Damage

Insect on Tree

Insects can do real damage to the trees growing in your yard. Most of the time, it’s easy to spot insect damage because you can see insects crawling, flying, and buzzing around your tree, and most of the damage done will be to the tree’s exterior. Here’s what you should be on the lookout for:

  • Leaves that look “chewed” or bitten – Beetles and some caterpillars feed on tree leaves. Too much damage to too many leaves can prevent your trees from getting the sunlight and nutrients they need.
  • Leaves with unusual colors – Aphids, leaf hoppers, and other insects can damage leaves, causing them to turn yellow or develop a “speckled” appearance.
  • Moldy bark – Aphids, lacebugs, and other insects excrete substances that can cause mold to grow on your trees, potentially causing long term damage.

Protect Your Investment

There are just so many benefits to having trees in your yard: they’re beautiful, can make you happier, and even make your property more valuable!

You should think of your trees as an investment that needs your attention to keep paying off. With just a bit of care and attention, you’ll be able to enjoy your trees for decades to come!

Ask a Professional

If you’re seeing evidence of these common tree problems and diseases, don’t worry. And if you’re at all worried about the health of your trees, don’t worry.

Contact NW Arbor Culture online or call us at (503) 538-8733 for a free consultation and estimation. We’re happy to come out, take a look at your trees, and let you know our expert opinion. We have over 30 years of experience caring for trees in the Portland area and know how to make sure your tree lives a long, healthy life.

Photo Credit: K. Kendall, Ash Kyd, John S. Quarterman, Robert Taylor, S. Rae, Carolyn Tiry, Forest & Kim Starr, AJ Cann

Tree and Landscape Pests of the Pacific Northwest

Tuesday, May 20th, 2014

Bugs play a very important role in the health of your trees and garden.

Pollinators, like bees and butterflies, allow the plants around your home to flower and produce fruit. Ground beetles eat vegetable munching slugs and snails in your garden. Spiders help reduce the population of disease spreading mosquitoes and flies.

Bugs on the trunkWhile bugs can be beneficial to our fruit trees and gardens, there are also many critters that can cause extensive damage and death to your plants.

This article will educate you about several common plant pests of the Pacific Northwest. We will help you identify some of the symptoms of harmful infestations. Reviewing the steps you can take to defend your garden and landscape from pest damage.




Aphids are one of the most common plant pests. They suck the sap from trees and plants causing the leaves to curl and die. Aphids also release excess sap from their bodies often causing plants to mold.

These frequent bugs come in several different colors and can affect any plant from roses to hardwood trees. Their bodies are usually 1/10th of an inch long and are easy to spot on the leaves and stem of your plants. Aphids have a short reproductive periodAphid Infestation (10-14 days) and a population can explode in no time.

But how can you hope to control an Aphid outburst in your yard?

Treatment – A small infestation can be wiped away with a cloth or blasted off with a garden hose. Sprays made of household soap and water or garlic oil can help prevent aphid growth as well. Avoid insecticides that can kill helpful bugs in your garden.


Spider Mites


Spider Mites are tiny mites that feed on the leaves of many different plants. With eight legs and miniature bodies, they pierce the protective surface of leaves and create tiny holes. The plant then loses water through the open holes causing the leaves to dry out and die.

These bugs are so tiny that the best way to detect them is by holding a piece of white paper under the suspected infestation. After gently tapping on the leaf or branch you will be able to see tiny black flecks that are moving on the paper.

Spider Mites can infest indoor and outdoor plants of all kinds. In the Northwest, Spruce Spider Mites are can be found on many of our common conifer trees like Doug-fir, pine and spruce. Also infesting arborvitae and other common ornamental shrubs.

Treatment – Similar to Aphids spider mites can be hosed off of plants and sprayed with a soapy water mix. Spruce Spider Mites require an addition application of ‘horticultural oil’ to kill eggs surviving through the winter.


Insect Borers


Common insect borers include the Asian Longhorned Beetle and the Bronze Birch Borer. This type of large bug tunnels into the trunk and branches of plants and trees. Often attacking hardwood trees such as maples, ash, and elm. The bugs then lay eggs in their tunnels effectively blocking off water and nutrientSmall poplar borer (Saperda populnea) sitting on leaf.s from traveling through the tree.

An infestation can be identified by large holes in and sawdust at the base of your tree. Yet, often times it can be too late to save a tree once it is infested.

Treatment – Insecticides can kill insect borers but are not always very effective. The best way to avoid an infestation is to keep your plants and trees healthy.

Insect borers and many other pests are attracted to dead and dying wood. If you prune, water, and fertilize your trees, they can naturally fight against insect borer infestation. Make sure to remove any fallen branches and dead wood around your trees that might also attract these pests to your healthy plants.


Preventing Insect Infection


There are many different harmful bugs that can infest your trees and garden. But the key to preventing general insect infestation is keeping your plants healthy. A healthy garden harbors a diverse population of beneficial bugs. Many of which eat and destroy the common insect pests we discussed in this post.

Cherry-blossom-treeKeeping your plants watered, fertilized, pruned, and mulched can help maintain your yards natural defenses against invading insects.

But, If you find an infestation in your yard that is out of your control, don’t hesitate to call a professional. The experts at Northwest Arbor Culture Inc. are not only arborists, but master gardeners, as well. We know how to control any infestation and can help you salvage your plants and trees. Before it’s too late.


Have you ever had a insect infestation in your yard? Let us know the methods you used and the challenges you experienced in the comments section.

Category Landscaping, Pests, Tree

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