What Do Oak Trees Need to Live?
Oak trees are some of the most recognizable trees in the American landscape. Easily identified by their acorns and elongated, multi-lobed leaves, oaks are adaptable enough to grow in a variety of conditions -- provided certain needs are met.
Oak trees generally thrive in moist, well-drained soil. Neutral to slightly acidic soil with a pH between about 6.0 and 7.0 is ideal for most oak trees. Deep, fertile soil is best, but it is not always available in a landscape setting. Oaks can generally make do with average soil, but avoid sand or heavy clay.
Water & Sunlight
Most oak trees grow best in full sun or partial shade. Oaks have moderate water needs, and can withstand periods of excessive moisture or moderate drought. Avoid planting them in a spot where the soil is very dry or routinely saturated with water. Locations where water collects after a rain are not ideal for most oak trees.
Oak trees are relatively low-maintenance. Supplemental water is helpful to newly planted trees, but established oaks generally do not need irrigation except in periods of serious drought. Fertilizer is also usually not needed. You can prune your oak tree during summer, removing only dead and broken branches.
Certain oak trees are adapted to slightly different conditions than others. Water oak and willow oak, for example, grows better in moist, swampy sites than other oak varieties. Talk to a local expert or consult your state's university extension to help you choose oak trees that are suited to your local conditions.
Oak trees are in our poems, songs and legends. Oaks are part of the Quercus genus, and there are about 600 species. The Roman poet Virgil once wrote, “Full in the midst of his own strength he stands, stretching his brawny arms and leafy hands.” Red oaks have leaves with pointed lobes and small bristles at the tip. Black oak trees have smooth, gray bark and its leaves turn bright red in the fall. Willow oaks have thin, straight leaves, resembling those of a willow tree. Willow oaks grow 60 to 75 feet tall. These oaks prefer the warm, coastal Southeast, but they will grow inland in protected areas. Pin oaks make a nice shade tree. Acorns mature after a year, and these trees sprout soon after falling to the ground. Varieties include chinkapin, post oak, bur oak and white oak. But one day, it will be 50 feet high. This oak will be found further north and west than other oaks. Live oaks are often seen draped in Spanish moss and bring to mind images of southern weddings and historic small towns. Symptoms are most severe in dry summers because the bacterium blocks the water-conducting vessels that move water from the roots to the leaves. Leaves usually remain on the tree until they drop in the fall. Symptoms show on red, scarlet, black and pin oaks. It is spread by root grafts, so it affects trees in close proximity. Because of their size and longevity, oaks are symbols of honor, nobility and wisdom. Later, many parishes adopted an oak to be the Gospel Oak, and springtime ceremonies would take place beneath it. Plant oak trees where they’ll have a lot of room to grow. A good rule of thumb is to give an oak space to grow 80 feet tall and 80 feet wide. Most oaks can grow as far north as zones 4 and 5, and some varieties can grow in zone 3.
- California Oak Mortality Task Force: Maintaining Oak Tree Health
- Clemson University: Oak; Debbie Shaughnessy, et al.; 2006
- University of Nebraska: Trees for Nebraska- Oak
- University of Tennessee: Plant the Right Tree in the Right Place; Wayne K. Clatterbuck, et al.
- Gardening Know How: Oak Tree Identification Guide for Gardeners
- University of Maryland Extension: Why Oak Trees are Declining
- Trees for Life: Mythology and Folklore: Oak
- Bios Urn: Symbolism, Information and Planting Instructions
- Oregon State: Common Trees of the Pacific Northwest: Oaks
- Arbor Day: Oak Trees: There's an Oak Tree Where You Live
- Fast Growing Trees: Oak Trees