Oak trees are some of the most beautiful and beneficial trees you can have in the landscape. When given enough space to grow, these trees can become massive specimens that provide many functions.
Oaks provide food and shelter for hundreds of caterpillar species. Supported by the oak tree, these caterpillars grow into pollinators like moths or become an important food source for birds and other wildlife. Acorns from oaks feed birds and other animals. Like other trees, oak roots help prevent soil erosion and their leaves help slow down rainfall. The shade these giant trees produce helps to cool the earth and provides shelter for insects, birds and mammals.
There are several oaks native to the region that you may want to consider planting.
Northern red oak (Quercus rubra) grows 50 to 75 feet tall and wide. Its leaves are dark green in summer, turning a brown-red color in autumn. Red oaks prefer full sun but can tolerate medium to dry soils. They are hardy to Zone 4. You can find your location’s USDA Plant Hardiness Zone by entering your ZIP code at https://planthardiness.ars.usda.gov.
Growing 50 to 80 feet tall and wide, Eastern white oaks (Q. alba) are hardy to Zone 3. They prefer medium to dry soils and full sun. White oaks have dark green leaves, becoming brown to red in autumn.
Another variety of white oak, the swamp white oak (Q. bicolor), grows 50 to 60 feet tall and wide, in full sun. True to their name, this species prefers moist, wet soils. Autumn color varies from reddish-purple to yellow.
Given their size, it’s best to plant oaks where they will have enough room to grow. An oak planted in the middle of a field with no other trees to compete with it will have a lovely, symmetrical form. Oaks can be planted closer together but try to space them spread apart at least 75% of their mature expected size.
The leaves of oaks are thicker and tougher compared to other tree leaves like maples. While this characteristic may be a nuisance for lawn care, these leaves are a benefit for insects that overwinter in leaf litter. If possible, plan to avoid mowing under the oak canopy so the leaves can be left to decay naturally and provide habitat for overwintering insects and pollinators.
Oaks are prolific seed producers and if you’re so inclined, you can collect acorns and start new oak seedlings to share with friends, family and neighbors. Just keep in mind that acorns require time in cold storage (stratification) before planting, typically around three to four months or longer depending on the species. Alternatively, leave the acorns for wildlife to eat or store for winter.
For information on trees and other home gardening questions, the University of Vermont Extension Master Gardeners Helpline is available to help at https://go.uvm.edu/gardenhelpline.
If you have a lot of space and are looking for trees that provide enjoyment for humans and tons of ecological benefits, consider planting a majestic oak.
by Bonnie Kirn Donahue, UVM Extension Master Gardener
Featured photo: The broad canopy of the swamp white oak provides ample shade and shelter. Photo by Debra Heleba
