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Weed Information

Weed Information Sheet

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Ash

Botanical Name

Fraxinus excelsior

Family

Oleaceae (olive) family

Also known as

Common ash, golden ash, European ash

Where is it originally from?

Europe, West Asia, North Africa

What does it look like?

Large, deciduous tree (to 30 m), with irregular, spreading crown, scattered branchlets with corky white pores, and large, black leaf buds. Large leaves are made up of 9-13 pointed leaflets (up to 10 x 3.5 cm) with serrated margins, paired along the midrib, which is hairy on the underside. Flowers lack petals, are very small and purple, appear in dense clusters (in September-October) before the leaves, and are followed by seeds (1.2-1.5 mm long) with a large wing (2.7-4 cm long) attached to one end. Seeds mature in autumn.

Are there any similar species?

Several species of ash are cultivated in New Zealand. F. excelsior can be distinguished by the number of leaflets and green midrib.

Why is it weedy?

Large size, long life, and fast growth rate make this a problem weed. Tolerates full sun to part shade and rich to poor soils.

How does it spread?

Seed is dispersed by wind.

What damage does it do?

Competes with native species for space, and shades smaller plants and trees.

Which habitats is it likely to invade?

Riverflats, forest, shrubland, scrub and waste places.

What can I do to get rid of it?

  1. Hand pull or dig out seedlings and small saplings (all year round): Mulch.
    2. Cut trunk and paint stump (all year round): cut trunk near to the ground, and swab freshly cut stump with metsulfuron-methyl 600g/kg (5g/L).
    3. Bore and inject (all year round): drill holes 20 cm apart around the trunk and inject each with 2 ml metsulfuron-methyl 600g/kg (20 g/L).
    4. Overall spray (spring-summer): metsulfuron-methyl 600g/kg (5g/10L+ penetrant).

What can I do to stop it coming back?

Monitor the site and treat any regrowth from the trunk or seedlings. Search out and remove the source of the infestation. Where appropriate plant native trees or shrubs to produce shade.

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