Oak trees will bring beauty to a home landscape

Of all the magnificent trees that shade our yards and line our streets, the most bountiful are oaks.

“Oaks feed more wildlife than any other trees in our region,” said Spencer Campbell, Plant Clinic manager at The Morton Arboretum near Lisle. Their leaves feed hundreds of kinds of insects whose caterpillars are food for birds and many other animals. Their acorns are an important source of fat and protein for squirrels, blue jays, deer, and countless other creatures. “Oak trees are the foundation of our local ecosystem,” Campbell said.

They’re also splendid. Oaks’ mighty trunks and spreading branches give them deep cultural associations with strength and longevity. Some species have a rich red fall color. To celebrate these trees, many local organizations participate in OakTober (chicagorti.org/program-oaktober).

Should you celebrate OakTober by adding an oak tree to your yard? “If you have the space in full sun, and you choose the right species for your soil conditions, planting an oak is a wonderful way of contributing to the future,” Campbell said.

As with any tree, there are things to consider before planting oaks. They have a reputation for growing slowly. Campbell says that’s not especially true, although some oak species take more time than others.

Oaks produce acorns, which some people find messy. This is a mast year when oak trees in an area all seem to produce a bumper crop of acorns at the same time, so acorns are plentiful. “Think of all the animals that are feasting,” he said.

Most oaks are large trees, so you do need plenty of room to accommodate them. “It’s very important to be realistic about how big an oak tree will grow,” he said.

For smaller yards, there are hybrid cultivated varieties bred to have a narrower form, such as Crimson Spire™ (Quercus ‘Crimschmidt’); Kindred Spirit® Ware’s oak (Quercus x warei ‘Nadler’); and Regal Prince® Ware’s oak (Quercus x warei ‘Long’). “Bear in mind that when we’re talking about oaks, ‘narrow’ may still mean 15 or 25 feet wide,” Campbell said.

If you have room for one of our glorious native oaks, consider these species. Learn more about these oaks, and many more species that would grow well here, at mortonarb.org/search-plants.

Swamp white oak (Quercus bicolor): This all-around-tough tree tolerates alkaline soil, clay soil, dry sites, occasional flooding and even road salt. It grows 50 to 60 feet high and wide.

Bur oak (Quercus macrocarpa): Notable for huge acorns that bear a certain resemblance to hedgehogs, this tree also tolerates a wide range of soil conditions and grows 70 to 80 feet tall and wide. Its thick, corky bark evolved to protect the tree from prairie fires.

Hill’s oak (Quercus ellipsoidalis): With striking red fall color, this species is a much better choice for most sites in the Chicago area than the somewhat similar pin oak. “Pin oak can’t handle alkaline soil, which is common in the region,” Campbell said. “Its leaves will usually turn yellow,” a condition called chlorosis. Hill’s oak also would prefer acid soil, but it is much more tolerant of high pH than pin oak.

White oak (Quercus alba): Massive and majestic, this monarch of Chicago-area ecosystems can spread its stalwart branches up to 100 feet wide. It needs plenty of space and well-drained soil. It is the state tree of Illinois.

Northern red oak (Quercus rubra): One of the faster-growing oaks, this tree has russet-red fall color and grows 60 to 75 feet tall and wide. Although it prefers acid soil, it tolerates alkaline and clay soil relatively well.

For tree and plant advice, contact the Plant Clinic at The Morton Arboretum (630-719-2424, mortonarb.org/plant-clinic, or plantclinic@mortonarb.org). Beth Botts is a staff writer at the Arboretum.