What is it?
Despite its silver coated leaves, this creeping groundcover is no little treasure. Aluminium plant, also known as artillery plant, is often found in gardens growing in the cooler areas around trees and shrubs. It has pleasant smelling, mint-like leaves, square, purplish stems, and hairy, soft lemon-yellow flowers in summer.
Why is it wicked?
Like tradescantia, (wandering jew or wandering willy), aluminium plant rapidly covers large areas of ground with a thick mat that stops seedlings of other plants from establishing. It is shade tolerant, so can be a problem deep into bush areas, as well as on the margins. Stems take root wherever they touch the ground, and it is also spread from stem fragments dumped with garden waste.
What can you do?
Handweed smaller areas of aluminium plant, taking care that all stem fragments are removed from the site and safely disposed of at a refuse transfer station. Large infestations of aluminium weed can be sprayed with a suitable herbicide.
For more control information, check out the weed search at www.weedbusters.org.nz.
For a striking evergreen groundcover, try the native bidibidi (Acaena microphylla) which is available in bronze red or blue-green cultivars, or pratia (Pratia angulata) which has white flowers followed by red berries in summer. Other alternatives include bellflower (Campanula portenschlagiana) and bugle flower (Ajuga reptans), both of which have blue flowers.