Northern Pin Oak

Northern Pin Oak Quercus ellipsoidalisThe northern pin oak (Quercus ellipsoidalis) is also called Hill's oak, yellow oak, and jack oak. It is similar to the red oak but does not get as large and is heavier branched. The northern pin oak can be found in northeastern Iowa on moist, sandy soils and clay upland.

Hardiness: Varies with the species of oak tree, ranging from zone 3 through 9.

northern pin oak leaf
Northern Pin Oak Leaf - Photo by Paul Wray, Iowa State University

Growth Rate: Slow to Moderate

Mature Shape: Broad, rounded

Height: Varies with species. Often maturing between 50 to 75 feet tall. Capable of growing upwards of 100 feet.

Width: 40 to 70 feet; varies with species

Site Requirements: Best growth in moist, well-drained soils. Adaptable to adverse soil conditions.

Leaves: Alternate, simple, lobed. Lobes have pointed tips. 

Flowering Dates: March - May

Seed Dispersal Dates: Late August - Early December

Seed Bearing Age: 20 years 

Seed Bearing Frequency: Abundant crops every 2-3 years

Seed Stratification: Prechill for 2-3 months at 34°F to 40°F

The leaf lobes are bristle tipped, with lobe sinuses reaching almost to leaf mid-vein. The leaves are leathery in texture, dark shiny green above.  The twigs are bright reddish brown to dark gray-brown.

The acorn is oval with the cap covering almost one-half. The edge of the cup is not deeply fringed.

The tree has a pale yellow, thin underbark.  The outer bark is rather smooth, with shallow, connected fissures.  It is dark brown near the base of tree to gray brown above.

northern pin oak acorns on a twig
Northern Pin Oak Fruit - Photo by Paul Wray, Iowa State University

Diseases that Can Affect Northern Pin Oak

Insects that Can Affect Northern Pin Oak