Bur Oak
Quercus macrocarpa

Location in Ontario
Bur Oak grows throughout the Deciduous Forest Region and northward. It prefers moist bottomlands or limestone soils.


Huge Bur Oak, Holiday Beach Conservation Area, Essex County
 

Genus Quercus
The ten Oaks of Southern Ontario are divided into two categories. Red Oaks have lobed leaves which are pointed and acorns (seeds) that develop over two years. White Oaks have leaves with rounded lobes or simple leaves with sharp teeth and acorns (seeds) that develop over one year. Acorns are a one-seeded nut with a tough shell, and a scaly cap which attaches to the tree. Often, Oak leaves stay on the tree over winter. Oak leaves on the ground are slow to decay, as this is a survival strategy to prevent the growth of other plants nearby. Oaks are monoecious with male (pollen) flowers and female (seed) flowers on the same tree. Oak is a favoured wood for flooring and furniture.


8 Oaks of University of Guelph Arboretum L to R: Shumard, Hill's, Bur, Chinquapin, Dwarf Chinquapin, Red, Swamp White, White. Missing: Black Oak and Pin Oak

In the Landscape
Bur Oak is a medium tree reaching 25 m in height, and can live to be more than 300 years old. It is a tree of medium height but with wide spreading branches. Leaves do not decay readily and persist under the tree along with acorns.


Bur Oak, University of Guelph Arboretum

Leaves
The leaves have rounded lobes in varying patterns, often broad at the top and narrow at the bottom. Leaves turn red in the fall.
Bark
The bark has thick, dark gray scales.
Flowers
Bur Oaks are monoecious with male (pollen) flowers and female (seed) flowers on the same tree. Flowers are contained in catkins. Flowers appear with the leaves and are wind pollinated.
Fruit
Bur Oak has good seed crops every 2 to 3 years, after 35 years of growth. Acorns have a shaggy fringe along the edge of the cap and mature in one year.

Wood
Bur Oak wood is hard and heavy with a beautiful grain. It is used for furniture and flooring. It is sold as White Oak.
Specific gravity: 0.64
Janka Hardness: 1370 lb
Wood Comparison Chart


Leaves and young acorns

Link to United States Forest Service Silvics Manual for Bur Oak.

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