Mislabelled Plant Turns Out to be Pest

Forest and Bird, Issue 312, 1 May 2004, Page 7

Mislabelled Plant Turns Out to be Pest

—SARAH GIBBS

ardeners who think they an ecologically friendly garden of native grasses may in fact be harbouring a noxious weed. Mexican feather grass, or Nassella tenuissima, is popular for its attractive light-coloured foliage and fluffy seedheads, but is a major ecological weed. Unfortunately some nurseries mislabelled Mexican feather grass as a native poa tussock grass. Although it was withdrawn in late 2001, it had already made its way into gardens and is still being unintentionally distributed by people who do not realise it is a noxious weed. It can germinate, grow to maturity and seed within four months. Each plant produces

thousands of wind-dispersed seeds each season and is capable of out-competing native ground-cover plants in a wide range of habitats. It is also unpalatable to stock. Mexican feather grass is closely related to nassella tussock, or Nassella trichotoma, a highly invasive native plant of Argentina which has cost New Zealand millions of dollars to control to date. Mexican feather grass is on the National Plant Pest Accord list, which means it is illegal to sell, propogate, commercially display or distribute it. The National Plant Pest Accord originated from the Forest Friendly Award scheme. This scheme was developed by Forest and Bird in 1993 to

encourage plant outlets not to sell plants that were environmental weeds, and was quickly adapted by government agencies. In some regions where Mexican feather grass is still

not widespread, such as Auckland, councils are trying to eradicate it. Contact your regional council if you think you may have Mexican feather grass in your garden.