Figure 1 Beautiful shape of a Bur Oak
Figure 2 Bur Oak native range
Figure 3 Beautiful oak flooring
Figure 4 Acorns feed many animals
Figure 5 Flowers
Common Name: Bur Oak
Family Name: Member of the Beech family - Fagaceae
Genus Name: Quercus
Species name: macrocarpa
Subgenus: member of the white oak subgroup – Lepidohalanus
Region of origin: Great Plain states
It is found as far north as Manitoba and south to Texas. It is found from the east, New Brunswick to Wyoming.
USA – North America to Canada
Tolerant of a variety of conditions. It can withstand drought due to deep root system established early. It is found in the bottom areas of the Mississippi River and along dry slopes of the Ohio River. It is found between the prairie and eastern forests. It is very hardy and resistant to fires.
Size at Maturity
Height: 50 to 80 feet, sometimes up to 100 feet
Girth: 2-3 feet diameter
50 to 80 feet
Can live to 200-400 years
In urban areas: It depends on the conditions and buildings nearby.
These trees are used for lawns, parks, fields, golf courses. They provide good windbreaks and are drought tolerant. They are also used for railroad ties, flooring, fence posts, and cabinets.
Wild animals eat the acorns. The inner bark was used by Native Americans to treat many medical issues (3).
Site characteristics and preferences:
The bur oak prefers at least six hours of full sun per day. They grow well in acidic, alkaline, loamy, sandy, well-drained, wet and clay soils (2).
Cold hardiness: Zones 3-10
Growing season: Spring through fall.
Moisture: They prefer moderate moisture, but have some drought tolerance.
Prefers south side with six hours of full sun.
The male flowers produce pollen, and the female flowers produce eggs that will be fertilized once the flowers are pollinated.
Imperfect flowers: They have both male and female flowers on the same tree but are often wind pollinated. The inconspicuous flowers emerge shortly after the leaves appear,. Male and female flowers are borne in separate catkins on the same tree on the current year's branchlets. Male catkins have greenish brown flowers. Females are with green scales and tinged with red (3).
Perfect flowers that contain a functioning male part and a functioning female part.
It can self-pollinate, but typically wind pollinates.
The flowers emerge after the leaves, from late April to mid-June.
Fruit is a round to egg shaped nut (acorn), ½ to just under 1 inch long, set in a dome-like cup around the base that is fringed with thick, coarse, brittle hairs, on a stalk up to ¾ inch long (4).
Seed bearing age is 30 years old. They can produce light to heavy acorns. Optimum seed production between 75-150 years. Seed taste bitter. Mast-year: Oak trees synchronize. All of the oak trees in a region equally overproduce acorns. Mast-years occur every two to five years.