Weed trees: Celtis
Noxious weeds are plants which cause problems to the natural and urban environment. They are often 'introduced' species that compete with native flora and spread easily. The City of Sydney manages plants the State Government declares noxious weeds and we rely on the community to help us keep such species under control.
Noxious weeds and some other problematic plants are exempt from our laws – you don’t need permission to prune or remove these species. Noxious weeds include the castor oil plant (Ricinus communis), willows (Salix spp.) and the Rhus tree (Toxicodendron succedaneum).
Chinese Hackberry (Celtis sinensis) is a native tree of China, Korea and Japan that is considered an environmental weed in Australia. The species grows up to 12–20m tall and is deciduous. Its leaves are glossy, with a paler underside and pronounced veins. It flowers in late winter and spring.
Unlike other Celtis species (refer to Celtis australis images below), the Chinese Hackberry has a serrated leaf edge in the upper half of the leaf only. It produces small berries 7–8mm in diameter, which turn reddish brown when ripe in autumn and early winter. The berries are distributed by birds and flying foxes. Seedlings often start to grow around residential and commercial properties, usually in the cracks and crevices of footpaths, paved areas and driveways. As they grow, the plants can cause structural damage to these surfaces.
In urban bushland areas, some are found in Glebe, young trees grow in a wide range of soils and can quickly colonise the area. The plants grow in dense groups, dominating native plants and damaging the ecosystem.
What to do with Chinese Hackberry on your property
If you spot Chinese Hackberry seedlings on your property, remove them before they get established. This will stop them spreading and you won’t need to worry about removing a large, poorly located tree in the future. Small seedlings and plants can be removed by hand or dug out.
Planting new vegetation will help reduce the Chinese Hackberry re-seeding and decrease its impact on the environment. Larger specimens (up to 10m high) can be removed by a professional tree company without the City’s approval. The stump of the tree may need to be 'grubbed out' or poisoned to stop the tree from re-sprouting.
All trees over 10m high are protected by the City of Sydney and approval is required to prune or remove any tree.
Last updated: Friday, 13 June 2014