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TREES & plants

Hill's oak

Hill's oak has excellent red fall color.

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.

This plant has some cultivated varieties. Go to list of cultivars.

 

Botanical name: 
Quercus ellipsoidalis
All Common Names: 
Hill's oak, northern pin oak
Family (English): 
Beech
Family (Botanic): 
Fagaceae
Tree or Plant Type: 
  • Tree
Foliage: 
  • Deciduous (seasonally loses leaves)
Native Locale: 
  • Chicago area, 
  • Illinois, 
  • North America
Planting Site: 
  • Residential and parks, 
  • City parkway, 
  • Wide median
Landscape Uses: 
  • Parkway/street, 
  • Shade tree, 
  • Specimen
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 (Chicago), 
  • Zone 6, 
  • Zone 7
Soil Preference: 
  • Acid soil, 
  • Moist, well-drained soil
Acid Soils: 
  • Prefers
Alkaline Soils: 
  • Intolerant
Salt Spray: 
  • Intolerant
Soil Salt: 
  • Moderately Tolerant
Drought Conditions: 
  • Tolerant
Poor Drainage: 
  • Intolerant
Planting Considerations: 
  • May be difficult to find in nurseries, 
  • Messy fruit/plant parts
Ornamental Interest: 
  • Fall color
Season of Interest: 
  • Mid fall, 
  • Late fall
Flower Color & Fragrance: 
  • Inconspicuous
Shape or Form: 
  • Oval
Growth Rate: 
  • Moderate
Transplants Well: 
  • Yes
Wildlife: 
  • Birds, 
  • Cavity-nesting birds, 
  • Migrant birds, 
  • Small mammals
More Information: 

Tree & Plant Care

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

Disease, pests, and problems

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 not harmful.

Disease, pest, and problem resistance

Tolerant of high soil pH so chlorosis is not a problem

Native geographic location and habitat

Hill's Oak (Quercus ellipsoidalis)acorn of Hill's Oakphoto: John Hagstrom

C-Value: 4

Commonly found in dry, upland sites

Bark color and texture 

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; 3 to 6 inches long.
Dark green in summer, changing to red in fall.  Dried leaves remain on tree into winter.

Flower arrangement, shape, and size

Male flowers in dangling catkins; female flowers smaller and held close to the stem.  Not ornamentally important.

Fruit, cone, nut, and seed descriptions

Acorns, 1/2 to 3/4 inch long with a slightly elongated shape.  Cap covers about 1/3 of the nut.

Cultivars and their differences

Majestic Skies(Quercus ellipsoidalis 'Bailskies'):  New foliage of this cultivar emerges red, then matures to a dark green and finally changes to red in fall.

Quercus ellipsoidalis or Hill's oak