Osage Orange

In Iowa the osage orange (Maclura pomifera) is a medium-sized tree, 50 to 60 feet in height, has  been widely planted in hedges. It grows with a short trunk and upwardly arching branches, forming a low, rounded crown.

Hardiness: Zones 4 through 9

lumpy, green, ball-shaped osage orange fruit
Osage Orange Fruit - Photo by Paul Wray, Iowa State University

Growth Rate: Fast

Mature Shape: Irregular

Height: 30-40 feet

Width: 30-35 feet

Site Requirements: Full sun; adaptable to most soil conditions

Leaves: Alternate, simple, with thorns or spines present

Flowering Dates: April - June

Seed Dispersal Dates: September - October

Seed Bearing Age: 10 years

Seed Bearing Frequency: Yearly

Seed Stratification: Prechill for one month at 34°F to 40°F

The leaves are 3 to 5 inches long and do not have teeth along the margin. They are thick, firm, and dark green in color. The buds are partly hidden in the bark and the terminal bud is absent. The twigs have thorns that are straight and 1/2 inch in length.

The fruit is round, wrinkled, pale green in  color and 4 to 5 inches in diameter. It consists of numerous small seeds crowded and grown together to form the characteristic "orange." When crushed, the pulpy fruit gives a bitter, milky juice.

The bark on young twigs is green. On older trunks it is orange-brown and deeply furrowed. The inner bark is bright orange. The bark of the roots is also a bright orange color and furnishes a yellow dye.

osage orange trunk showing bark
Osage Orange Bark - Photo by Paul Wray, Iowa State University

osage orange leaf
Osage Orange Leaf - Photo by Paul Wray, Iowa State University

osage orange twig showing thorns
Osage Orange Twig - Photo by Paul Wray, Iowa State University

osage orange white flowers
Osage Orange Flowers - Photo by Paul Wray, Iowa State University