What is it?
Like a giant version of the much loved busy Lizzies, shrub balsam can reach up to 2m in height. It has green, hairless, succulent stems, and pale pink flowers that are present most of the year.
Where is it found?
Shrub balsam is an old garden favourite that ‘jumped the fence’ and took off into the wild. It is often found in gardens of old homesteads, and around holiday homes in coastal areas.
Why is it wicked?
Shrub balsam is a fast growing pest shrub that is hard to control. Stems take root wherever they touch the ground, so it spreads by ‘layering’ itself into bush and wetland areas, forming dense stands that crowd out native vegetation. Like that other weedy pest, tradescantia, shrub balsam is shade tolerant, so it can move deep into bush areas.
What can you do?
Shrub balsam plants can be dug out or larger infestations can be sprayed – check out www.weedbusters.org.nz/weed_info/detail.asp?WeedID=24 for more information on control methods. As this weed tends to be spread into bush and wetland areas through the dumping of garden waste containing fragments of stem and roots. To prevent the risk of spread, take all parts of this plant to a refuse transfer station for safe disposal.
Try the native rangiora (Brachyglottis repanda) which also has large, soft leaves, or kawakawa (Micropiper species) which grows well in the shade. Other options include Dichroa versicolor with its large, hydrangea-like leaves and purple flowers, and the orange-flowered fire lily (Clivia minata) which thrives in shady conditions.
Weedbusters is an interagency weeds awareness programme supported by all regional councils and unitary authorities, the Department of Conservation, Biosecurity New Zealand, Federated Farmers, Biodiversity New Zealand, NZ Landcare Trust, Nursery and Garden Industry Association, NZ Biosecurity Institute, and NZ Plant Protection Society.