Since you live in the Pacific Northwest, there’s a good chance you have many trees around your home. While these trees may not require as much care and attention as your flower beds or garden, you don’t want to just ignore them!
Taking some time twice a year to give your trees a little TLC will ensure they continue to increase your curb appeal, provide a pleasant landscape for you to enjoy, and not endanger your home.
Keep reading to learn the most important tree maintenance tips from our arbor experts.
First Things First: Know Your Trees
Here in Oregon and Washington, there are a wide variety of beautiful tree species. As you can probably guess, these different types of trees require different care.
Do you know what kind of trees you have on your property? Here at Northwest Arbor Culture, we are happy to help you identify the type of trees living around your home. The Arbor Day Foundation also has an easy-to-use tool for identifying trees.
Once you’ve honed in on the type of trees you’re living with, you should aim to learn the unique needs of each species. A few things to make a note of include:
How much water the tree needs and its preferred soil type
Whether or not the tree is drought tolerant
Any unique stressors, such as a low tolerance to high winds or overwatering
Make Sure Your Trees Get Enough Water
Here in the rainy Pacific Northwest, most trees get plenty of natural water. However, during the summer you may need to give your trees some extra help as an extended drought combined with sunny days is an easy way to kill off your trees.
Make sure you’re giving your trees a good soak a few times throughout the summer. This will ensure your tree and its soil remains healthy. During the winter, on the other hand, you can let your trees sit dormant.
The only exception would be if your tree has been recently planted within the last year. In this case, you’ll want to encourage its growth by making sure it has enough water. A good rule of thumb is that your new tree needs 5 gallons (1.5 inches of rainfall) every week.
Mulch A Few Times a Year
If you’re not familiar, mulch is made of decaying leaves or bark and is used to enrich and/or insulate the soil of your tree. Mulch will not only help protect your tree and its roots from distress, it also looks great.
A new layer of mulch placed around your tree a few times a year will keep soil moist and control weeds. Just keep in mind that you’ll need to use the correct amount. Too much mulch piled up around your tree can cause trunk rot and disease. Too little will defeat the purpose of the mulch in the first place.
How to Apply Mulch Around Your Tree
When applying mulch, the most important thing is to avoid choking your tree. Leave some space around the tree trunk, starting the mulch about 3-6 inches away from the base. Make about a 3-foot circle of mulch around your tree, about 3 inches deep
What Kind of Mulch is Best?
Only use mulch from a reputable source. Avoid just taking some from your neighbor’s leftover mulch pile. These leftover piles may contain materials from diseased trees and will cause more harm than good.
You can make your own mulch by combining materials from your own yard, such as healthy lawn clippings, shredded leaves, branches, and bark. Otherwise, if you have questions about what type of mulch to buy, give us a call. We’d be happy to help.
Your Tree Bark Matters
The bark on your tree is its natural armor against infection, disease, and rot. As you’re mowing your lawn or weed whacking around your property, take care not to knick your trees. Similarly, keep an eye out for anything else that might be causing regular damage to the bark of your trees.
Keep Pests Out of Your Tree Branches
Here in Oregon and Washington, we’re lucky to be surrounded by lots of beautiful wildlife. While animals like deer, squirrels, and raccoons can be fun to observe, they can also damage your trees if you’re not careful.
If you’re in an area that sees a lot of deer or has a rodent issue, there are a few steps you can take to not only protect your trees, but your entire yard and home. Keep in mind that a rat in your tree can usually scurry along branches and find a way onto your roof.
Here are some ways to keep pests out of and away from your trees.
Install deer fencing around your tree or the perimeter of your home
Add trunk guards to your trees to keep rodents away
Use a pest control spray along the perimeter of your property, if necessary
Don’t Forget to Prune Your Trees Regularly
Pruning is perhaps the most involved tree maintenance task you’ll need to perform. It’s also one that needs to be performed carefully. Improper pruning can prompt disease to spread, destabilize your tree, and in extreme cases, make it fall over.
We recommend hiring a professional arborist to handle the task– especially if you’ve never pruned a tree before. Pruning your trees, especially if they are large trees, can be dangerous and cumbersome. Working with a licensed, certified arborist will ensure your trees remain a safe, healthy, and beautiful part of your property.
If you want to go at the pruning process alone, here are some best practices to follow:
Remove dead or broken branches.
Get rid of crossing branches which are rubbing against each other and damaging the bark. Typically, you should remove the smaller branch, encouraging the stronger branch to continue growing.
Remove low branches, branches prone to damage, or branches encroaching on your house or roof
When cutting back to a main stem or branch, avoid making a flush cut. Leave a small collar of the branch, which will help protect your tree against pathogens
Even with all this in mind, be aware pruning techniques can be specific to each type of tree. It’s always best to consult a professional arborist before undertaking a large pruning job.
Count On Northwest Arbor Culture to Care for Your Trees
Need some extra help maintaining the trees on your property? Whether you need tree pruning or removal, are concerned about the health of your trees, or want to improve the overall landscape of your property, we can help.
Northwest Arbor-Culture Inc. is a full-service tree care, landscape, property maintenance and forest management provider. For over 30 years, we’ve been providing services to homeowners and businesses in Portland, Vancouver, and the surrounding areas of Oregon and Washington.
We are proud of our reputation for being the most dependable, professional, and educated team in the Northwest. We offer quality services at a fair price and unmatched customer attention.
Contact us to learn more or call us at (503) 538-8733 to schedule a free estimate.
Recently, 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!
Birds
So many different species of birds live in Portland area trees! Here are a few of the most common:
House Finch
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
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
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
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
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
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
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
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!
Mammals
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.
Raccoon
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
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
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 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.
I can’t think of another city with as much greenery and as many beautiful trees as Portland, can you? The Portland area is home to Forest Park, one of the biggest urban parks in the United States and it’s just filled with beautiful evergreens. Then there are all the other parks scattered around town, which often have unique trees of their own, including fruit trees, elms, oaks, cedars, maples, and many others!
Everywhere you look there are interesting trees to see! Today we’re going to talk about some of the most interesting and notable trees around, Portland’s Heritage Trees!
What is a Heritage Tree?
The Portland City Council maintains a listing of trees that are unique and notable due to their:
Size
Historical importance
Horticultural interest
Other unique values
Together, these special trees are known as Portland’s Heritage Trees! Altogether, since the program began in 1994, more than 300 trees have been added to the Heritage Trees database and more are being added every year! There are even extra-special trees that are known as Trees of Merit.
How Does a Tree Become a Heritage Tree?
Anyone can nominate a tree as a Heritage Tree! Every year, dozens of applications are received and only the most interesting and important trees are added to the registry. Here’s how the nomination and approval process works:
During June, the tree will be inspected to see if it should move forward in the process
During the Fall, the Urban Forestry commission reviews and approves a select few trees to join the Heritage Tree registry!
Visit Portland’s Heritage Trees!
Now that you know what Portland’s Heritage Trees are, how and where can you see them? Heritage Trees are found all over town– in private backyards, in city parks, in cemeteries, and pretty much everywhere you look!
Each Heritage Tree in Portland is marked by a commemorative plaque detailing important facts about the tree, including its species and when it was certified as a Heritage Tree. Of course, just walking around looking for trees with plaques nearby isn’t the best way to see the variety of Heritage Trees that are on display.
Luckily the City of Portland Parks Department provides a few great resources!
Heritage Tree Maps and Guides
When you’re at your computer, check out this great map featuring all of Portland’s Heritage Trees! You can zoom in and even see pictures of the trees, right on the map!
If you prefer paper to a computer screen, check out this downloadable, printable guidebook to Portland’s Heritage trees. It features over 60 pages of maps, pictures, and information about Portland’s most special trees!
Of course, when it comes to Portland’s Heritage Trees, there’s also an app for that! You can download the PDX Trees App for your iPhone. It’s 100% free and includes interactive maps and lots of great information!
Heritage Tree Walking Tours
While you can plan out your own route to visit Heritage Trees, there’s a great (and free!) book called From Stumptown to Tree Town, a guidebook featuring a walking tour that highlights a few historical Heritage Trees and uses them to tell the story of Portland’s history! It’s a great resource and you can download it for free right here.
Heritage Tree Podcast
If you’re interested in learning more about specific trees, check out the Heritage Tree Podcast, a series discussing the history and importance of some of Portland’s most notable trees! The podcast was created as part of a student project at Portland State University and you can listen to all of the episodes and read more about the project here.
A Few of My Favorite Heritage Trees!
While there are about 300 Heritage Trees in Portland, a few stand out to me:
Corbett Oak at Heritage Tree Park
You’ll find this beautiful, historic oak in one of Portland’s smallest parks, Heritage Tree Park in Southwest Portland!
Osmanthus in the Chinese Garden
Here’s a fun one! This Heritage Tree is actually inside of the Lan Su Chinese Garden in downtown Portland. You can’t tell from the picture above, but there are high-rise office and apartment buildings less than a block away. The Chinese Garden is a great place to relax amid the hustle and bustle of downtown!
Douglas Fir in Forest Park
Near Balch Creek in Forest Park, you’ll find the tallest Heritage Tree, a Douglas Fir standing nearly 250 feet tall! It’s about 100 yards from the stone house on the Lower Macleay trail. If you’ve never hiked in Forest Park before, you’ll love it! The start of the trail is just a few minutes from downtown.
Do You Have a Heritage Tree in Your Yard?
What does it mean to have a Heritage Tree on your property? First the good news! You’ve got a piece of Portland history in your yard and you should be proud of it. But you also need to be aware of your responsibilities.
Heritage trees can’t be removed without approval from both the Urban Forestry Commission and the City Council. Plus you’ll need a permit before pruning or cutting any branches from a Heritage tree!
If you have a Heritage Tree in your yard or on your property, contact NW Arbor Culture online or call us at (503) 538-8733 for a free consultation. We can help you figure out if your tree is healthy or if it needs a little TLC!
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.
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
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 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
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.
Age
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.
Construction
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
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
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
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.
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.
Trees have a ton of benefits: clean air, beauty, fruit, and shade, to name a few. But did you know they can also prevent flooding? It’s true! “The typical medium-sized tree can intercept as much as 2,380 gallons of rainfall per year,” the USDA says.
To understand how, let’s look at why flooding happens. Without trees, rain runs off soil and into rivers and streams, raising the water level. Trees help keep soil in place, and their roots soak up water. (This is called reducing erosion and anchoring topsoil.)
Even trees’ leaves help prevent flooding. When raindrops bounce off them, the water doesn’t hit the ground as hard. “Gentler rain causes less erosion,” explains the Why Files.
The Trouble with Deforestation
We need paper. It’s just a fact. Life would be pretty sad without books, envelopes, dollars, coffee filters, board games, or photographs. But clear-cutting forests, aka deforestation, makes flooding worse. The Why Files explains again: “In terms of flooding, the unimpeded raindrop impact on bare ground leads to heavy erosion and quick runoff.” Without trees to soak up water, lessen rain’s impact, and hold soil in place, rain runs faster off land.
Clear-cutting trees has another side effect. Since the soil isn’t anchored in place by tree roots, it gets carried downstream by heavy rainfall. And the dirt and mud washes into rivers and streams, which means riverbeds get clogged and can carry less water. That makes flooding worse.
Welsh researchers at the Centre for Ecology & Hydrology noticed this and partnered with farmers to reduce runoff. As reported in The Guardian:
[Farmers] noticed during rainstorms their newly planted woodland seemed capable of absorbing vast quantities of water while grazed land let rain pour down hillsides. So they invited the scientists to study the land.
“We measured rain that was being absorbed by grazing land and by woodland, and found the latter was 60 times more effective at taking up water than soil on land grazed by animals,” said [Dr. Zoe] Carroll [of the Center for Ecology & Hydrology]. “We expected to find a difference, but not one of this magnitude.”
Pretty cool, right?
Urban Flooding
Trees don’t just prevent flooding in the forest or countryside. Trees play a big role in lessening damage from flooding in cities as well. Think about it: Concrete doesn’t do much to stop or soak up rain. Water runs across the top of pavement, not into it. Trees and soil, on the other hand, can act as a sponge.
Rainwater which lands on trees either evaporates to the air or drips down to the ground below, where it can soak into the soil. Surface water from nearby areas can also flow into the permeable area around the trees, which further increases the amount of water that can soak away and reduces demand on stormwater drains.
In fact, in a 2013 research study, scientists found that trees soaked up twice as much rain as asphalt, reducing runoff by about 60%.
So does just any tree help prevent flooding, or are certain ones better than others? I’m glad you asked. Depending on the tree’s location, you may want to plant different types. For instance, bald cypress or water tupelo trees have a high tolerance for water, so you can plant them at the bottom of a basin. (Houston is doing just that.) Other types of trees are more sensitive to being in standing water for long periods of time. Such conditions can kill the roots and eventually the entire tree.
In general, you want to plant native trees. One writer suggests the following:
Silver maple
California laurel
Blackgum
Sandbar willow
Here in the Pacific Northwest, planting broad-leaf evergreen trees is wise. Deciduous trees — those that lose their leaves in the winter — do less to intercept rainfall, since their leaves are gone.
The benefits of trees don’t stop at slowing water flow. Trees also clean the water and improve its quality. When trees soak up water through their roots, they can keep toxins and pollutants from going into drinking water by releasing them as a gas through their leaves.
Planting trees gives you a ton of benefits, from cleaner air and water to less flooding. Contact us at Northwest Arbor-Culture, Inc. if you want to talk with a certified arborist about getting some trees planted!
Recently, we talked about some of 
