Flickweed

Flickweed, also called hairy bittercress, is a low-growing winter annual broadleaf weed common in garden beds, pots, nursery containers and thin turf across southern Australia. It germinates in autumn, grows through winter and sets seed in spring, often completing its whole life cycle in just a few weeks under mild, moist conditions.

The plant forms a basal rosette of leaves close to the ground, with each leaf made up of several small, rounded leaflets arranged along a stalk, the end leaflet being the largest. Leaves are mid to dark green and slightly hairy, giving the plant its common name of hairy bittercress. From the centre of the rosette, thin upright flowering stems 5 to 30 cm tall emerge, bearing tiny four-petalled white flowers only a few millimetres across. These are followed by narrow, upright seed pods (siliques) about 2 to 2.5 cm long that stand out from the stem.

The seed pods are the key identifying feature. When mature, they are under tension and burst open explosively at the slightest touch, flicking seed up to a metre or more away, which is how the weed spreads so quickly through garden beds and potting mix. A single plant can produce hundreds of seeds, and repeated germination flushes can occur through a mild winter and into spring.

Flickweed is managed by removing plants before seed pods form, since any disturbance to a mature plant scatters seed further. Hand pulling or hoeing young rosettes is effective while the soil is moist, and mulching garden beds thickly helps suppress germination. In turf, maintaining a dense, well-fed lawn through autumn reduces the bare, open ground the weed needs to establish.