Suppose you’re considering planting a tree in your yard this spring. There’s one kind of tree that you see all over your neighborhood, and it really catches your eye. Could that be the one?
That particular tree might not be such a good idea, say horticulturists and arborists. Forests are filled with a variety of trees, and neighborhoods should be, too.
“The best thing you can do in an area is maintain a diversity of species,” says Charles Tubesing, plant collections curator at Holden Arboretum. “Sometimes it’s a good idea to plant something that your neighbors don’t have. It’s good to have genetic diversity so one pest can’t have an impact on the whole area.”
Lauren Lanphear of Forest City Tree Protection in South Euclid agrees.
“If you plant several of the same tree in your yard, if one gets a problem they will all get that problem,” Lanphear says. “The same can happen in a neighborhood, too.”
Take, for example, emerald ash borer. On emeraldashborer.info, the pest is described as an exotic beetle that was discovered in southeastern Michigan near Detroit in the summer of 2002. The adult beetles nibble on ash foliage but cause little damage. The larvae, however, feed on the inner bark of ash trees, disrupting the tree’s ability to transport water and nutrients.
Emerald ash borer probably arrived in the United States on solid wood packing material carried in cargo ships or airplanes originating in its native Asia. Since its discovery, the insect has killed tens of millions of trees in southeastern Michigan alone, and tens of millions more in other states, including Ohio.
“Ten or 15 years ago, you didn’t hear of emerald ash borer,” Lanphear says. “A lot of communities planted them, and suddenly the pests come. To diversify is good.”
Planting a variety of trees in a given area is important, but there are other ways to be sure the tree you plant is healthy, lives long and can fend off pests.
The first is doing some research on the tree or trees that you fancy. Don’t make a rash decision about a tree because you like the flowers that it produces in spring or the color that the leaves turn in the fall. Find out what the proper growing conditions are, e.g., sun exposure, type of soil and drainage.
According to one forestry website, the No. 1 cause of tree death outside of forests is planting the wrong tree for the setting.
Says Lance Walheim, an expert with Bayer Advanced lawn and garden products, “It really does pay to look around.”
It’s not a bad idea to have your soil tested before planting. Know how tall and wide the tree will grow so that you don’t end up with branches brushing against electrical wires or slapping against your roof.
Once you discover that a particular tree is likely to do well in your yard, find out where it was grown.
“It’s really good, if at all possible, to get plants grown in Northeast Ohio,” says Lanphear. “Ask the nursery or your landscaper what kind of climate it was grown in. If it was grown in Tennessee, it might not do well [here].”
Buy a high-quality tree. That might mean visiting a nursery or getting recommendations from neighbors.
Follow the planting and maintenance instructions. These include the depth and width of the hole, mulching, fertilizing, watering, etc. Trees that become stressed from improper planting and care are more susceptible to pests, say Tubesing and Lanphear. What’s more, stressed trees actually give off odors that attract insects.
Keep in mind that all insects aren’t harmful.
“It’s not a bad thing for trees to have insects on them,” says Tubesing. “Insects are part of the outdoors. Oftentimes, trees support a population of insects that depend on them for their life cycles.”
Says Lanphear, “Just because you see an insect, that doesn’t mean you should grab something and spray.”
If you spot an insect that makes you uneasy, take a picture of it and look it up online, or go to a garden center or arboretum for advice, says Walheim.
There are some tree and shrub protectants that are systemic, meaning the liquids are poured into the trunk and then absorbed into the tree, Walheim adds. But with any chemicals, follow the instructions to the letter.
Walheim, a citrus farmer who has authored or contributed to more than 30 gardening books, including the best-selling “Roses for Dummies” and “Lawn Care for Dummies,” likes the idea of planting a native tree.
“There are a lot of great native trees that get overlooked,” he said. “I call them trees that need a friend.”