The Banana passion-fruit vine (Passiflora mollissima) has become a problem plant for the Otago Peninsula over recent years and has continued to occupy significant areas of roadside in Portobello and Harington Point Roads. Given its highly invasive nature and need for high light levels passion-fruit has begun to choke the life out of many areas around the Peninsula. Its prolific fruit production has also been shown to be a suitable source of food for possums and birds distributing viable seed from the gut that can germinate. The other issue is if this plant remains widespread on roadside areas it will eventually be problematic to conservation groups and agencies as well as private landowners who manage bush remnants on the Peninsula.
I have raised the issue of passion-fruit at our Community Board meetings and through The Star to highlight the need to look at a multi-agency approach to management of passion-fruit. That includes both the Dunedin City Council and Otago Regional Council. As a land manager one of the issues for the City Council is understanding the extent of the problem and how to tackle it on the roadside areas. With in mind Moira Parker and myself have completed a map of the roadside areas on the Peninsula using GPS waypoints. The extent of the spread of passion-fruit surprised me with 220 sites identified and mapped. This mapping exercise now gives the City Council some hard data to develop a programme of suitable control, but it won’t be easy. This has to be looked at as a long-term and constant project over the course of 6-7 years and discussions with the Council will be ongoing. In the mean time one of the most simplest things people on the Peninsula can do is eat more passion-fruit! By harvesting the fruit it reduces the opportunity for further seed dispersal. If you are eating the fruit or preparing it just remember to dispose of seed and vine material in your refuse, not your compost!
The map below shows the 220 sites identified predominantly on roadside areas. You can navigate around it within the frame by using your mouse. Click on one of the markers and you’ll see a photograph of the site. You can also view the map in a full screen view by clicking on the box icon on the top right corner.