Cudweed (Gamochaeta spp).
In Australia there are two common species in turf and lawns. These are G. coarctatum (Grey cudweed) and G. americanum (spiked cudweed), and these are annuals or short lived perennial weeds.
After you finish reading this you will be able to:
- Identify Cudweed.
- Know the conditions that favour its establishment.
- Know the best cultural and chemical options to control it.
Spiked Cudweed usually only produces upright flowering stems. Its leaves have glossy green and have no hair on their upper surfaces. Dense white or silver hairs cover the underside of the leaves.
Some of these only have this hair on the underneath of the leaves, and others have this hair on all surfaces. Its small flower heads exist in elongated leafy clusters at the tips of the stems. Grey Cudweed is up to 15 cm high.
Cudweeds spend winter as small basal rosettes. In the spring they then usually grow an upright stem, and have grey-green, tooth-edged leaves. The seedheads have a cover of distinct fine, white “woolly” fibres.
How to Identify Cudweed.
Cudweed has egg shaped leaves with a dull light green surface and a white underside. The weed forms clumps once it establishes, and it then produces pink to purple flowers through the Spring and Summer.
Category: Broadleaf (Dicot).
Flower: The pink to purple flowers develop from Spring to Summer.
Height: It is from 10-30 cm high.
Leaf length: Basal leaves are in a rosette, and are spathulate or obovate. The basla leaves are 5–12 cm long. This weed has alternate stem leaves, which are 1–6 cm long.
Leaf width: The leaves are 8–20 mm wide.
Comments: Cudweed stems have a felty mass of matted hairs. The upper surface of the leaves are green with a furrowed pale mid vein.
Habitat: Cudweed prefers freshwater areas, such as lawns or sports turf, and garden beds. It also sometimes grows on the edge of saltwater areas or swamps and disturbed areas.
How to remove Cudweed from your lawn.
Cultural control.
Certain cultural practices, limit and prevent the establishment of Cudweed. The aim is a thick, health surface as Cudweed tends to grow in bare areas and favour, a thin weak cover.
If Cudweed is not too widespread it can be physically removed by hand. However, if there is a lot of this weed then chemical control may be the best option. This weed is a prolific seed producer which can multiply quickly through seed dispersal, so use of pre-emergents will go a long way to prevent this weed becoming established.
Chemical control.
Several post-emergent herbicides are available for Cudweed. At Gilba Solutions, we recommend Warhead Trio and Contra M herbicides. (Don’t use Contra M on Buffalo grass.)
