What black ash trees look like

Size and shape

  • Smaller tree with a narrow crown.
  • Grows to 15 to 20 metres in height.
  • Trunk reaches 30 to 50 centimetres in diameter.


  • Deep green, hairless leaves with jagged edges.
  • 15 to 30 centimetres long.
  • Oval-shaped on a central stalk with a slender pointed tip.
  • 7 to 13 opposite leaflets per leaf.
  • Full leaves, as opposed to single leaflets, tend to drop in fall.


  • Light grey.
  • Soft and cork-like on young trees.
  • Older bark has thin, flat scales.


  • Female flowers are feathery and yellowish, up to 5 centimetres long.
  • Male flowers are red or purple, up to 3 millimetres long.
  • Male and female flowers occur on separate trees.
  • Blooms in early spring before leaves appear.


  • Narrow, oblong or elliptical seeds.
  • Hang in clusters that stay on the tree over winter.
  • 2 to 5 centimetres.
  • Seeds are winged.

Where black ash is found

Black ash grows across Ontario except in the Far North. It is one of the last trees to leaf out in spring and among the first to turn yellow and drop leaves in fall. These trees grow well in moisture and are commonly found in northern swampy woodlands.

Emerald ash borer is threatening black ash across its range. This tree species is now considered endangered in Ontario. Find out what we are doing to protect the black ash by reading the recovery strategy.

What you need to know to grow black ash

  • Moisture: grows in wet areas.
  • Soil: grows best in rich soils.
  • Shade: intolerant of shade.
  • Cautions: If infested, emerald ash borer will eventually lead to tree death.
    • Use compost fertilizer to increase the rate of growth.

Benefits and uses of black ash

Wildlife benefits

Trees provide shelter for insects, birds and mammals. Birds and small mammals feed on the seeds. Butterfly and moth larva feed on the leaves.

Commercial uses

The wood from black ash trees is used for:

  • lumber
  • tool handles
  • baseball bats
  • furniture
  • trim and flooring
  • fuelwood

Fun facts about black ash

  • Black ash is also called basket ash, as it was used by some Indigenous peoples to make baskets.
  • Black ash range extends further north than other ash species found in Ontario.
  • About a quarter of the global range of black ash is in Ontario.