Contact your local county Extension office through our County Office List.

Close Icon
Master Gardeners enhance Colorado communities through outreach, education and environmental stewardship.

Green Ash   arrow

Fraxinus pennsylvanica (frak’-si-nus pen-sil-va’-ni-ka)
Family: Oleaceae, Olive

Key Steps


Green Ash leafLeaf: Oddly pinnate, 5-9 leaflets, egg-shaped, long pointed tips, wedge base. Smooth margin below the middle, slighlty toothed above. Shiny green. Petiole slightly “winged”.

Bud: 1/2 inch long or less, 2-3 pair of brown, fuzzy scales. Terminal bud and two nearest lateral buds from a shape like a king’s crown made of suede.

Leaf Scar: Half circle or shield-shaped, straight across top. Many bundle scars from a continous half circle within leaf scar. Bud sits at top of leaf scar. leaf scars do not meet across stem.

Stem: Gray-brown, pale lenticles, stout, stiff, compressed at nodes. Long ridges. May be hairy.

Bark: Vertical ridges form a diamond-shape; ridges are flat on top like they’ve been planted.

Pith: Six-sided, white

Flower: Green to reddish-purple, tiny.

Fruit: Samara, single wing shaped like a canoe paddle. Pointed at top, round at other end. 1 to 1 3/4 inches long.

Habit: Large shade tree to 60+ feet tall by 30 feet wide. Several main branches, irregular spreading.

Culture: Adaptable to many soils. Moderate moisture requirement. Extremely prone to Liliac/Ash Borer in strees and restricted root spread sites.

Cultivars: ‘Marshall’s Seedless’ – no fruit, ‘Summit’ – narrow upright, with fruit. ‘Emerald’ – seedless, dark green foliage.