Blackberry canes grow to six feet or more on the periphery of the wetland area. As well as being a food source, they provide good cover for small birds.

Galls, which are particularly noticeable in winter, grow on the stems. The color is variable as they change from green to red and then brown with time. These galls are probably caused by a small wasp belonging to the Cynipidae family. Eggs are laid in the stem and the larvae feed on the plant tissue of the resultant swelling.