Planting a tree is like making an investment. A maple tree is like the dot-com stocks of a year ago–it goes up really fast. An oak is more like a government bond, slow to mature but solid as the earth.
Although they’re slower getting to the payoff, oaks make up for it by developing into commanding trees. They look good close-up, where you can appreciate their lobed leaves and ridged bark, and from a distance, standing together in a natural grove or spreading their broad arms above a billowing prairie.
Particularly in the fall, when their leaves go various shades of red, orange and russet, oaks are the most glorious trees in our local landscape. They’re our Plant of the Month for October, when even people who are normally indifferent to the trees around them can’t help noticing a rich red oak.
“None of the big maples and the rest have the size and the majestic shape our oaks have,” says Connor Shaw, who owns the Monee tree nursery Possibility Place. “And there’s nostalgia associated with oaks. You think of oak furniture and acorns. They’re historic trees.”
If they’re so great, how come oaks are so hard to get going in home landscapes? Shaw and Cliff Miller, head of the Lake Bluff landscape design firm P. Clifford Miller, both say it’s because we try to hurry oaks along.
Homeowners often want an instant landscape, so they pay for big oaks because they know the trees are relatively slow growers. But oaks’ roots are more delicate than those of many other trees and they don’t take transplanting easily. Miller says the stress of the transplant can lead to dieback and bug infestations–and even slower initial growth than the tree could have had.
The simplest way to avoid transplant stress, Miller and Shaw agree, is to start with small oaks. Their root balls are so small that they’re far less likely to be damaged in transplanting, and if any recovery time is needed, it’s short. The tree will start putting on size far sooner. Besides, both oak experts say, an oak planted small will eventually get bigger than one planted big, because of its low-stress youth.
Shaw suggests starting with oaks whose trunks are 161/2 to 2 inches in diameter; that’s about 6 to 8 feet high, and priced from $100 to $250.
The usual slam on oaks is that they grow too slowly, but Terry McLoughlin, an arborist who owns McLoughlin Tree Care in St. Charles, says “They grow just fine if you put them where they want to be.” Annual growth of a foot or more is normal for well-handled oaks after their first year in the ground, Shaw says.
The essential way to avoid stressing an oak is to plant it in the right conditions. Most must be grown in full sun. Here are some of the best oaks for Chicago-area yards, with notes on their needs.
White oak (Quercus alba) is the Illinois state tree. Its leaves have deep round lobes and go a rich burgundy in fall. A white oak can top out at about 80 feet high. It must be grown in moist soil. Miller says white oaks are finicky in one important way: They need relatively acidic soil. If your soil ph is above 7, don’t plant a white oak. Miller recommends a chinkapin oak, Quercus muehlenbergii, as a substitute in those more alkaline soils.
– Swamp white oak (Quercus bicolor) is true to its name. It can’t take a dry setting. “If you have a seasonally wet depression in your yard, you want a swamp white,” Miller says. The leaves aren’t very lobed, but they go nice shades of orange in the fall. Swamp white oak can get to 60 feet high and wide, and according to Morton Arboretum studies can tolerate urban conditions well. It prefers slightly acidic soil, but isn’t as picky as the white oak. An added attraction on swamp whites, which hail from a little south of here: “They have very cool peeling bark, almost like the river birch, that everybody loves,” Miller says.
– Bur oak (Quercus macrocarpa) is among the slowest-growing oaks, but when it gets where it’s going–up to 80 feet high and 90 feet wide–it’s incomparably statuesque. With deeply grooved bark and asymmetrically outstretched branches, an old bur oak is an amazing sight. It’s the variety that adapts to a wider range of conditions than most local oaks, Shaw says. “It can sit on a hill or in a floodplain and do fine,” he says. Miller recommends bur oaks for planting in the poor, disturbed soil of new subdivisions . “They’re a pioneer tree,” he says. “They’ll love it.”
– Pin oak (Quercus palustris) is loved for growing faster than other oaks and for its pointy, slim-waisted leaves that go deep reds and browns in fall. But McLoughlin believes homeowners often love it the wrong way. “They like it so much they stick it in the front yard,” where drainage has usually been engineered to drain water off the flat lawn, he says. Pin oaks can grow tall–up to 70 feet high and 35 feet wide–if given abundant water, but in drier sites such as lawns, most are forgotten and die young, he says. McLoughlin recommends planting pin oaks in depressions where water collects.
– Red oak or northern red oak (Quercus rubra) is the only one among these oaks that can take any shade–although light shade only, not the darkness below Norway maples. It’s a fast grower, eventually hitting about 75 feet high and 65 feet wide if planted in an acidic soil. The fat, pointy leaves go yellow and occasionally red in fall. McLoughlin warns, though, that red oak is the variety that most often has to be removed because of rotting inside.
