It’s the season for trees. Now, when they begin to shed their summer cloaks of green, revealing the shimmer of crimson and saffron underneath, they become the jewels of our landscape.
Rapt as we are, we head out to buy these statuesque features, perhaps unaware that unlike an impulse flat of annuals, trees deserve a more measured, considered approach.
“Even professional landscapers sometimes don’t think about the full spread of a tree when it grows up,” says Michael Gebhard Sr. of Gebhard Tree Service in Manheim. “They might look good closer together or next to a house when they’re small, but after 20-25 years when they grow up, they become a problem.”
Tree trimmers like Gebhard are quite familiar with the problem of wrong tree, wrong place. It’s what keeps them in business.
“People get busy and don’t realize what their trees are doing,” he says.
Years of inattention can lead to a sudden realization that tiny, spread out saplings are now creating a mosh-pit of unruly limbs in the landscape, or that water-loving trees have invaded and clogged the sewer lines.
“I had a lady last week who got trees from a magazine and planted them along her backyard when they were real small. She didn’t realize that they were willows and that she had way too small of a backyard for them,” he says. “After they started to really grow and she realized what she had done, she called me to take them down. It was a shame.”
Willow trees are one variety that can be especially problematic on small properties or too close to a home.
“They’re nice, as long as they’re way out in the backyard with lots of space to grow,” says Gebhard. “They do need to be pruned up with regular trimming, though, as they do tend to break apart.”
Bradford pears, once a staple of city street plantings relished for white clouds of fragrant spring blooms, now have fallen out of favor with their tendency to split.
“They’re nice, but they do blow down in storms pretty easily,” says Gebhard.
Sweet gums are also on his best-to-avoid list. “I would steer away from them. They’re a messy tree, their root system is shallow, and as they mature they’re more prone to storm damage,” he says.
As for evergreens to avoid, Gebhard advises against the ubiquitous white pine. “A lot of people plant them because they’re nice when they’re small,” he says. “But they’re really high maintenance. If you don’t keep them trimmed back, the snow beats them up and they can become a problem tree.”
Careful selection can help homeowners avoid these problems right from the beginning, providing more appropriate varieties to enhance rather than endanger their property.
Gebhard recommends homeowners consult with their landscaper or local nursery to settle on the most suitable tree for the specific site.
Do Your Homework
“When picking out a tree, take your time and do your homework,” says Bruce Stryker, vice president of York Tree Service, as well as co-owner of both Shades of Green and Shiloh Landscape and Design.
“A lot of decisions in plant material are in the eye of the beholder,” he says. Where he comes in is helping steer homeowners in more appropriate directions, offering alternatives to popular but notoriously problematic trees.
“Silver maples can be thought of as weed trees,” he says. “They’re fast growing, which is instant gratification, but the side effect is that they are poorly structured and soft wooded and have surface roots.”
Instead, he recommends planting “almost any other kind of maple—sugar or red—to avoid potential problems.”
The PAtrees.org website provides a wealth of information to help homeowners select the best trees for their site, describing how to analyze site conditions to ensure the trees they select will flourish.
Tree triage
But what if you’ve inherited a problem tree?
If it’s still small, Stryker recommends regular pruning to encourage the tree into a more structurally stable state.
“It’s better to prune a little more frequently than a lot all at once,” he says. “It’s good to be proactive, especially on faster growing or poorly structured trees like ornamental pears, silver maples, and crab apples.”
Gebhard says that judicious pruning can nip potential problems in the bud, especially this time of year before winter storms have a chance to turn a damaged tree into a dangerous hazard.
“When trees are going into the dormant stage, that’s the best time to prune,” he says.
If you know how to look at a tree with an eye for potential problems, you can spot early warning signs and prevent damage.
“It’s easy to see if a tree has a split or decay or dead branches that could come down at any time,” says Gebhard. “It’s harder to know when a tree has a branch that is overly thick or has a limb that is leaning with a lot of weight. Sometimes getting that weight off can prevent storm damage.”
He advocates thinning a tree in the late fall, when it’s easy to see how the limbs attach to the trunk.
“Look at how the limbs come into the tree: weak limbs come into a V shape at the crotch; stronger limbs are in a U-shape, which tends to break at the tip during a storm,” he says.
Stryker says that natural pruning (removing dead wood and pruning to maintain the natural habit of the tree) can be done year-round with the exception of the short window at bud break. But he says fall is the time to do crown reduction (“which should not be confused with topping a tree to make it look like a hatrack”). Stryker says that crown reduction is more “a nip/tuck of the crown to reduce its size and shape to lessen the potential of it splitting apart.”
The PAtrees.org website also lists numerous resources to help homeowners become educated on proper pruning techniques, including publications from Penn State University and the United State Department of Agriculture. The site also offers ways to help recognize and evaluate trees that are potential hazards.
In choosing an arborist, PAtrees.org suggests getting several references, asking for signed contracts, and ensuring they are certified and insured by asking to see the certificates.
Gebhard, who has worked in the business for more than four decades, says it’s important to find someone with years of hands-on experience.
“You can be book-smart about trees, but as far as skill goes, it takes a good four to five years to become really good at this,” he says.
If you do find you need to do more than trimming—that your tree needs to be removed—fall is also the most ideal time to plant a new one, according to Stryker.
“If all else fails, remove it and start again,” says Gebhard.
8 Guidelines for Selecting Trees from PAtrees.org
1. Selecting a tree that will survive and flourish isn’t always as easy as a trip to the garden center. We often select a tree for its aesthetic attributes such as showy spring flowers, fall color, or unique leaf or bark without even looking at the site and conditions it will have to grow in. Before you get your heart set on a certain tree for your yard, there are several things you need to look at and think about.
2. Evaluate the above and below ground growing space. If high voltage electric lines exist overhead, select a tree species that will mature at 25-30 feet, such as crabapple, tree lilac, hedge maple or ornamental cherry, to name a few.
3. Examine the soil texture, pH, drainage and compaction levels. If the soils are a heavy clay or drain slowly, that will limit species selection because many trees cannot survive in these soils. Soil pH is a measure of acidity and 7.0 or greater will not grow healthy oaks and red maples.
4. If the tree will be planted along a road or sidewalk, select a species that will tolerate de-icing salts.
5. Avoid selecting trees that have poor branch structure and are prone to branch breakage such as ‘Bradford’ Callery Pear, Willow, Poplar, Siberian Elm, or Silver Maple. Do not plant these close to homes or structures.
6. Avoid planting invasive species that will quickly take over a site and displace native plants, degrading habitat for native insects, birds and animals.
7. Avoid some species that are currently under stress and declining in our landscapes, due to introduced insects and diseases.
8. The best success will come from matching the planting site limitations with a tree that will tolerate those conditions.
