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Hill's oak

Quercus ellipsoidalis

Common names:
Hill's oak, northern pin oak

Content Detail

Hill’s oak, a Chicago region native, is very similar in appearance to pin oak, but has the advantage of tolerating a higher soil pH. This means that the chlorosis (yellowing) that is common in pin oak is not a problem for Hill’s oak. Hill’s oak can be used in parkways and has excellent fall color.

This species is native to the Chicago region according to Swink and Wilhelm’s Plants of the Chicago Region, with updates made according to current research.

  • Family (English) Beech
  • Family (botanic) Fagaceae
  • Planting site City parkway, Residential and parks, Wide median
  • Tree or plant type Tree
  • Foliage Deciduous (seasonally loses leaves)
  • Native locale Chicago area, Illinois, North America
  • Size range Large tree (more than 40 feet)
  • Mature height 40-75 feet
  • Mature width 40-75 feet
  • Light exposure Full sun (6 hrs direct light daily)
  • Hardiness zones Zone 4, Zone 5 (Northern Illinois), Zone 6 (City of Chicago), Zone 7
  • Soil preference Acid soil, Moist, well-drained soil
  • Tolerances Alkaline soil, clay soil, Dry sites, Occasional drought
  • Season of interest mid fall, late fall
  • Flower color and fragrance Inconspicuous
  • Shape or form Oval
  • Growth rate Moderate
  • Transplants well Yes
  • Planting considerations May be difficult to find in nurseries, Messy fruit/plant parts
  • Wildlife Birds, Cavity-nesting birds, Migrant birds, Small mammals
  • Has cultivars Yes

Native geographic location and habitat: 

Hill’s oak is commonly found in dry, upland sites from Missouri to Ohio and into Canada. C-Value: 4.

Bark color and texture: 

The bark is relatively smooth and gray. At maturity, shallow ridges will form at the base of the tree.

Leaf or needle arrangement, size, shape, and texture: 

Simple, alternate leaves with deep sinuses and bristle-tipped lobes are 3 to 6 inches long. They are dark green in summer, changing to red in fall. Dried leaves remain on the tree into winter.

Flower arrangement, shape, and size: 

The male flowers are in dangling catkins while the female flowers are smaller and held close to the stem. Neither are ornamentally important.

Fruit, cone, nut, and seed descriptions: 

The acorns, which are 1/2 to 3/4 inch long, have a slightly elongated shape. The cap covers about 1/3 of the nut.

Plant care: 

Hill’s oak is tolerant of dry soils, but moist, well-drained soils are preferred. It is tolerant of alkaline soils. Prune oaks in the dormant season to avoid attracting beetles that may carry oak wilt.

List of pests, diseases, and tolerances: 

Oak wilt is a potential disease problem. Insect pests include scale and two-lined chestnut borer. Galls caused by mites or insects are common, but are not harmful. It is tolerant of high soil pH, so chlorosis is not a problem

Majestic Skies™ Hill’s oak(Quercus ellipsoidalis ‘Bailskies’): 

New foliage of this cultivar emerges red, then matures to a dark green, and finally changes to red in fall.

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