Pampas grass looks good but the days of using it as a farm shelter are gone. In fact the days of planting pampas anywhere in NZ are gone as it is now illegal to sell or plant it.

Before October 1, the plant was not to be sold in Southland but farmers could source it via Otago, where it was still being sold, or by propagating existing plants. But as from October 1, the National Pest Plant Accord came into being which included pampas grass as a pest plant.

Keith Crothers, of Environment Southland, said the Accord reinforces that pampas grass cannot be sold throughout the country whereas before there were gaps in the system which allowed people to buy the plant outside of the region.

Mr Crothers said the plant has become a big problem further north, including the Nelson region, where it has infested bushlands and forest plantations.

Pampas grass is an invasive plant described as an "aggressive coloniser" with some female plants able to produce millions of seeds annually, which do not require pollination to germinate.

In Southland, pampas grass has not become a problem which could probably be put down to more good luck rather than good management. Mr Crothers said the plant has a reproduction system unlike many other plants, which means there are different sex plants. The seeds from female sex plants (pistillate) do not require pollination to germinate. It is believed the female variety of the plant has not established itself in Southland as yet and this is why it is not considered a problem in the region. However, Mr Crothers said, it would only be a matter of time for this plant to become established if people continued to source the pampas plants from outside the region. He believes the Accord will go a long way to minimise this problem occurring.

Pampas grass is a member of the Cortaderia family of which there is an alternative in Cortaderia richardii (a NZ native toi toi). This plant is being promoted as a good alternative to people wanting pampas. Its appearance is not dissimilar to pampas but instead of flowering in autumn it flowers in late spring. It is also not considered as rampant as pampas and does not bulk up quite the same.

Note: The Accord relates to C. selloana and C. juvata.

- Nov 10, 2001