Mullumbimby Couch

Mullumbimby couch (also called globe sedge or Kyllinga) is a low-growing perennial sedge, not a true grass, that spreads by wiry rhizomes and stolons just below or at the soil surface. It forms a dense, tangled mat that can crowd out lawn grasses over time, particularly in warm, moist conditions typical of coastal and subtropical parts of Australia.

The leaves are bright to mid-green, glossy, and folded with a distinct central crease, giving the foliage a slightly V-shaped cross-section typical of sedges. Stems are triangular in cross-section (the classic sedge giveaway) rather than round like grass stems. Leaves and stems usually sit flatter and denser than surrounding turf, creating visible patches of a different texture and colour.

Its most recognisable feature is the seedhead: a small, round to globe-shaped white-green cluster sitting just above the leaves on a short stalk, quite different from typical grass seedheads. These appear through the warmer months and persist even after mowing, since the plant sets seedheads low to the ground.

It's a serious lawn weed in home gardens because it tolerates regular mowing, spreads aggressively via both rhizomes and seed, and establishes readily in moist, poorly drained or compacted soil. It's commonly found in couch, buffalo and kikuyu lawns across the eastern seaboard, especially in Queensland and northern New South Wales, though it can turn up further south in warm, damp microclimates.

Management relies on improving lawn density and drainage to reduce the conditions it favours, hand-removal of small patches (making sure to dig out the rhizome network, as fragments can regrow), and avoiding over-watering which encourages spread. Persistent or larger infestations are difficult to control by mowing or hand-pulling alone and often need a sustained control program.