Climbing asparagus, Asparagus scandens Thunb.: a South African in your forest patch

Climbing asparagus, Asparagus scandens Thunb., currently has a patchy distribution in New Zealand, mainly in disturbed lowland forest remnants near towns and the coast, predominantly in the North Island but found as far south as Banks Peninsula. Here it prevents regeneration of native seedlings and smothers or strangles understorey shrubs and saplings. Based on its current distribution, it tolerates open sunny sites to deep shade and damp or dry forest. Left unchecked and aided by birds and humans, climbing asparagus is likely to spread considerably in the next decade, consolidating its current distribution in New Zealand. Several characteristics of the species make it difficult to control: the small, fine seedlings are hard to find, adult plants entwine with native plants, much of the plant’s biomass is underground and the apical meristem will resprout if left in the ground after control.