Tree Care August 28, 2023August 28, 2023

Let’s Talk About Tree Care

How does Friends of Trees set trees up for a long, impactful life?

Trees are one of the most cost-effective answers we have to the growing challenges of climate change. It’s a simple fact that we need more trees and native plants. But it’s not as simple as just planting them. To make sure that trees and plants survive and thrive, we need to invest in after-planting care. Watering, mulching, and regular inspection during a tree’s first three years, plus appropriate pruning in a tree’s first seven years, do wonders for setting that tree up to provide its full benefit for decades and beyond.

“In short, trees are cheap and human lives are valuable.”

-USFS Researcher Dr. Geoffrey Donovan, whose research found an association between trees planted by Friends of Trees and lower mortality (Learn more)

We’ve planted close to a million trees and native plants in the 34 year history of Friends of Trees. We know that they don’t all make it. But when we plant The Friends of Trees Way, we are working hard to ensure that trees and native plants flourish, so that they can shade our homes and streets, clean our air and water, and make our neighborhoods more liveable.

RIGHT TREE, RIGHT PLACE

Planting trees in an urban environment presents unique challenges to trees that would otherwise do well in a forest. Climate change complicates the matter even further. The success of a tree has so much to do with its specific environment—soil, space, sunlight, and moisture availability. Making thoughtful choices for each and every tree and green space planting site—and incorporating climate-adaptive species whenever possible—is a huge part of setting trees and plants up for success.

“The better we can guide folks to right tree, right place, the lower maintenance and longer lived our trees will be,” says Senior Neighborhood Trees Specialist Andrew Land. “Plant a shade-lover in full sun and you’ll either need to water it regularly to keep it looking fresh or you’ll need to replace it before long.”

POST-PLANTING INSPECTION AND CARE

The work doesn’t stop after a tree goes into the ground. We build three years of post-planting establishment care into our tree care plans. Making sure a tree is watered and mulched during those first few years is crucial. We train volunteers to serve as summer inspectors who visit trees twice during their first summer and make recommendations to the tree recipient as needed.

We also provide tree recipients with educational materials after the planting, send mailings and reminder emails. See our tree care guide here.

Hotter and drier summers in the Willamette Valley will make tree survival increasingly challenging regardless of who planted them. This is why Friends of Trees is encouraging funders to evolve our standardized three-year tree care model to five years of watering, summer monitoring, and periodic tree pruning.

COMMUNITY ENGAGEMENT

One of the reasons that the Friends of Trees tree planting model centers on community tree education and volunteerism is because it produces an extra layer of stewardship and protection for those trees planted by community members. By working with tree recipients, volunteer planters and volunteer summer inspectors, we help tree knowledge spread throughout the neighborhoods where we work, and more and more people become invested in the health of the trees and can help identify trees in need of assistance and care for them before it’s too late.

People want to plant trees, and that’s awesome! But we need support for post-planting care, too. At Friends of Trees, we don’t just plant a tree and walk away. It’s imperative to make sure that trees get the chance to flourish, especially in places like East Portland, a low-canopy area of the city that accounts for many of the city’s heat-related deaths.

Your support will help us expand our tree care program.

When a volunteer plants a tree, it often becomes sentimental and the volunteer becomes invested in seeing the tree healthily mature over the years. This is the sort of relationship with trees that we encourage with our tree recipients and volunteers. Trees are more than a utility to be managed. They provide benefits both tangible and intangible, and they enrich our lives and communities, more and more as they grow and mature.

Learn more about tree care here.

Tree Care March 20, 2023April 20, 2023

Leaflet: Watering

Determining Your Tree’s Watering Needs

We’ve had a wet April, which means your trees are getting plenty of water! But the transition from spring to summer can be a tricky time to determine when to water your tree. Come this time of year, we recommend watering once a week when the weekly rainfall is less than one inch. But you might find yourself wondering, “when did it rain last?” (You can check here!)

Too much watering is the most common mistake, but consistent watering is crucial to getting these young trees established. A good way to know if your tree needs water is to check the soil. Stick a garden trowel or even a pencil 2-3 inches into the soil. If the soil at that depth is dry to the touch, then your tree is ready to be watered.

Once the dry season settles in, watering once a week is a good schedule (pick a day to water and keep it up!). Deep watering is best for these newly planted trees. Give 10-15 gallons at a time. Water slowly so that moisture soaks deeply into the soil and water doesn’t run away from the root zone. Mulching is a great way to hold water in the soil for your new trees.

“I always say that roots are infamously “lazy” and grow in response to mild stress, just like human muscle,” says Neighborhood Trees Senior Specialist Andrew Land. “We lift weights to encourage human muscle growth, whereas we water deeply and hold off for a week to encourage roots to follow that water downward, which helps establish sinker roots to fend off future drought.”

Trees and perennials have more vast root systems that hold up for the long haul, and they need deep and infrequent watering. Flowers and annuals need more daily and superficial watering, which just doesn’t work for a tree. Tree roots are growing 12-18″ down and just don’t get enough benefit from daily irrigation that is intended to water lawns.

Either a gator bag, hose on a gentle trickle for maybe 20 minutes, or a 5-gallon bucket with three 1/8″ holes drilled on the side at the bottom and filled 2-3 times consecutively works great. It’s a good practice to move the bucket around the tree each time you fill it to ensure that the whole root system gets water. Think of it this way: we’re trying to simulate a rain storm, during which all parts of the root system will get water at about the same time and rate.

It’s important to note that dry and hot are two different things. In late spring and early summer, we may get some seemingly perfect weather, and you don’t think to water your tree because it isn’t hot outside. But regardless of temperature, a dry spell is characterized as 2-3 weeks without significant rainfall. It might not be hot out, but your tree still needs a drink!

If the temperature gets over 90 degrees, bump your watering schedule up to twice a week. If we see another heat “event” coming, a good, deep soak beforehand can help the tree survive.

Tree Care March 15, 2023March 16, 2023

Leaflet: Spring Tree Care

Spring has Sprung – What that means for your trees

Spring has truly come in fits and starts this year. Some of us might still feel like it’s winter, and some are ready to announce that Spring has sprung! Trees are the same way when it comes to breaking dormancy. Some are early risers, and some sleep in. A bunch of factors go into it, including species, daylight, and temperature.

Spring is the perfect time to notice seasonal cycles. The study of these periodic events in biological life cycles is called phenology. When does a tree go dormant, when do you start to see buds, how long is the growing season? We can see quite a range among species.

“Cornelian cherries normally bloom about this time of year,” says Neighborhood Trees Senior Specialist Andrew Land. “Whereas a few years back, someone approached me about an Oregon white oak that they thought was dead, until it finally broke bud in June.”

Andrew and other staff at Friends of Trees keep an eye on phenology as it particularly relates to survival. They take note of trends in trees’ responses to different stimuli like light and temperature, with the intent to prioritize the most climate adapted species.

Here are some things you can do to take care of your trees this time of year.

Mulch Madness

It’s a great time to refresh mulch as needed. The objective is to mulch the tips of the roots as they grow outward from the base of the trunk. They will grow into soil that’s moderate in temperature and contains moisture, factors that mulch will provide. Because the roots are growing outward, when you mulch trees in their second year in the ground, aim for more of a 4-5′ diameter ring of mulch, still 3” thick, about a foot from the base of the trunk.

You may have noticed that some trees hold their leaves through winter. They’re called marcescent leaves, and they are a sign of last season’s growth. You’ll see them on native oaks like Oregon white oak (Quercus garryana) and scarlet oaks (Quercus coccinea). Come spring time’s flush, these leaves will be shed to make room for new growth. You can use these leaves as mulch!

Go easy on the pruning

It’s best to go easy with regard to pruning during “bud break.” This is when sap is rising up the tree, after having dropped to the roots in the fall. As the sap is rising, some trees (maples, for example) will “bleed” if pruned as sap is rising. It’s not harmful to the tree—that’s where maple syrup comes from, after all—but it can be disconcerting to see.

Weekly Watering

It’s almost time to start weekly watering for newly planted trees. “Deep and infrequent” is the recipe for success. Starting mid-April, 15 gallons all at once, once a week is ideal. Either a gator bag, hose on a gentle trickle for maybe 20 minutes, or a 5-gallon bucket with three 1/8″ holes drilled on the side at the bottom and filled 2-3 times consecutively works great.

If the temperature gets over 90 degrees, bump that up to twice a week. If we see another heat “event” coming, a good, deep soak beforehand is very wise as preventative medicine.

More tree care here!

Tree Care February 15, 2023

Leaflet: Native & Climate-Adapted Trees

Considering Natives and Climate Adapted Non-natives

The right tree, right place ethos is complicated by urban environments and climate change

We invite you to consider the cascara (Frangula purshiana), a tree native to the Pacific Northwest. It has pretty autumn colors, does well in both shade and sun, and is a great backyard habitat tree, with small berries that attract native and migrating birds. This low-maintenance tree is a wonderful native option for your street or yard, and we still have plenty available in our tree store this season!

We’re big fans of native trees at Friends of Trees. It’s important to steward native plants as food and shelter for native animals, and in so many instances, natives are the right choice when you’re looking to put the right tree in the right place.

“There’s always a place for native trees in our hearts and in our gardens,” says Neighborhood Trees Senior Specialist Andrew Land. “But there’s also a place for non-native, locally hardy trees in the urban environment.”

The urban environment presents unique challenges to trees that would otherwise do well in a forest. Concrete and asphalt trap both heat and cold. The soil is often stripped of top soil and compacted. And trees are usually stranding alone, rather than part of a multilayered forest ecosystem.

Urban spaces are also usually a degree or two warmer than natural areas, which is only made worse by climate change. Some local species, like the western red cedar, are already struggling due to warmer temperatures.

“The climate is changing, and we can anticipate it continuing to change dramatically,” Andrew says. “So it makes sense to consider trees that would do well here, especially if they’re drought-tolerant free of pests and disease. We’re told to consider planting trees that thrive 500 miles south of here, because those should thrive here in 20 years based on climate change models.”

One such non-native is the ‘Persian spire’ Persian ironwood (Parrotia persica ‘JL Columnar’), a columnar cultivar of a tree native to Iran. It’s drought-tolerant, has no problems with pests or diseases, and is expected to do well as a street or yard tree in the face of climate change. It’s a great alternative to cascara that you should have no qualms about selecting.

Another is the swamp white oak (Quercus bicolor, shout out to our Year of the Oak!), which is native to eastern North America and one of our favorite oaks. It turns out that trees well-suited to swamps also do really well in urban environments. Their roots are accustomed to anaerobic conditions. Whether they’re underwater or under concrete, they can handle a lack of oxygen. 400 swamp white oaks were planted at the 9/11 Memorial in New York City.

The American hophornbeam is another great backyard tree. It’s native to eastern North America, and has flowers that look like hops, a characteristic that makes them feel right at home here.

“When it comes to considering trees for our urban forest, variety is really the spice of life,” Andrew says. “If a disease or pest takes out a particular species, you don’t want that to be the only tree you have. Diversity creates resilience.”

Tree Care September 28, 2022September 29, 2022

Emerald Ash Borer

What we can do in response

The discovery of the emerald ash borer in Oregon has many people rightfully worried about the fate of ash trees in our region. The Emerald Ash Borer, or EAB, is an invasive wood boring beetle that feeds on ash trees. There are thousands of wood boring beetles in the world, and most cause no problems at all, but EAB isn’t native to North America, where it has fewer natural predators and the ash trees have no natural defenses.

EAB was first discovered on the North American continent in Southeastern Michigan in 2002, likely brought in with wood packing material. Since its introduction, it has caused catastrophic tree deaths and slowly spread across the continent.

EAB has likely already been in our area for a few years; the amount of time that it takes for a healthy ash tree to die from EAB is 3-5 years, that is why we are seeing some of the first trees in active decline right now.

Ash trees make up 5% of Portland’s street tree canopy (1 in every 20 trees!) and there are 9,000 ash trees on streets and in parks of Eugene (with many more that haven’t been inventoried). In certain areas the absence of ash will be more stark than others. We will particularly notice ash trees dying in large numbers in certain natural areas (the Oregon Ash, Fraxinus latifolia) and in parking lots, where they are a popular landscaping tree. It is important to know that preemptively removing ash trees in large numbers will not stop EAB. The ash trees we have, as long as we have them, provide tremendous benefits to us and our environments

In response to the EAB’s arrival, some Friends of Trees staff members are taking trainings, doing research, and formulating our best response to the EAB presence in our community.

“We have a huge community of people with tree knowledge,” says Green Space Specialist Harrison Layer. “If we can accurately take notice of trees in distress, we can make a difference.”

What we can do:

Learn how to identify an ash tree.
Destroy ash trees that have died from infestation.
Give insecticide treatment to ash trees of distinction, important members of our community.
Plant a diversity of species in their place.
Find ash trees who do not succumb and appear resistant to Emerald Ash Borer, scientists need to know about these survivors with important genes!

“It gives me hope to think about finding trees that are resistant to EAB,” Harrison says. “It helps me imagine a future where we still have ash trees.” The USFS Dorena Genetic Resource Center south of Eugene has successfully bred disease resistance to blister rust in sugar and western white pines, and to Phytophthora lateralis for Port-Orford-cedar, giving hope for resistant strains of OR ash.

There are several natural predators of EAB, and EAB will likely cause a boom in native wildlife that eats EAB. Many birds, especially woodpeckers eat EAB larvae and pupae, and some native wasps have been documented to eat EAB larvae. Woodpecker activity on an ash is a hint that it could be infested with EAB. Sometimes blonde patches of sloughed off bark can be seen on the tree from woodpeckers, because EAB makes eating trails in the sapwood right under the bark surface.

EAB doesn’t infest ash trees less than 1-inch in diameter, meaning the ash we have planted in the Green Space Program the past couple planting seasons are immune for now.

Ash trees in decline will often feature defoliation from the top of the tree, epicormic growths (suckers from base), and have ‘D-shaped holes’ in their trunks. It is important to remember that the actual beetle can only be seen during its ‘flight period’ which is roughly between June 1st and August 30th.

“There are many green beetles that are native to Oregon,” Harrison says. “So it’s really important to correctly identify the EAB Beetle.”

While an EAB has the ability to travel up to 50 miles in flight, it doesn’t usually travel more than 10 miles in a year; furthermore, they typically settle on the next ash tree that they find, which is often much less than 10 miles away. It will take decades before EAB run out of food in our region.

Again, it is important to know that removing ash trees in large numbers will not stop EAB. The ash trees can still provide tremendous benefits as long as we have them. We will need to monitor the situation as long as we can to learn, adapt, and hopefully one day recover.