Cudweed (Gamochaeta spp).
Cudweed is a common weed of lawns, sports turf or garden beds, but will sometimes grow on the edge of swamps and disturbed areas. Several species with similar growth habits and control measures make up the Cudweeds. All the Cudweeds are actually members of the daisy family, and have many small flowers in each flower head.
In Australia there are two common species of Cudweed you find in turf and lawns. These are G. coarctatum (Grey cudweed) and G. americanum (spiked cudweed). Both of these are annuals or short lived perennial weeds.
- Spiked Cudweed usually only produces upright flowering stems. Its leaves are glossy green, and have no hairs on their upper surfaces. However, dense white or silver hairs cover the undersides of the leaves. It has small flower-heads on elongated leafy clusters at the tips of the stems.
- Grey Cudweed has spreading and/or upright flowering stems. Its very narrow leaves have a grey colour, and are densely hairy on both surfaces. Its small flower-heads are borne in elongated leafy clusters at the tips of the stems.
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.
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.
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).
Photosythetic Pathway: C3 Weed.
Flower: Cudweed flowers from Spring to Summer.
Height: It is from 10 to 30 cm high.
Leaf length: The spathulate or obovate basal leaves are 5 to 12 cm long, and are in a rosette. Cudweed has alternate stem leaves, which are 1 to 6 cm long.
Leaf width: The leaves are 8 to 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 is a weed of damp sites, gardens, lawns, roadsides, pastures, disturbed sites and waste areas. It sometimes grows on the edge of saltwater areas or swamps and disturbed areas.
How to remove Cudweed from your lawn.
Cultural control of Cudweed.
Certain cultural practices, limit and prevent the establishment of Cudweed. The aim is to produce a thick and dense turf surface, as Cudweed tends to grow in bare areas and favour, a thin weak cover.
Proper turf management is important for broadleaf weed control.
- Maintain a dense, turf cover by proper mowing, fertilizing, and watering practices.
- Mow at the right height for your turfgrass. Because Cudweed has a prostrate growth habit, it means it avoids mower blades if you cut your turf too high.
- Core and reduce traffic if possible to control any compaction and encourage desirable turfgrass competition.
- If Cudweed is not too widespread, you can remove it by hand.
Chemical control of Cudweed.
If there is a lot of this weed then chemical control is the best option. This weed is a prolific seed producer which mutiplies quickly by seed dispersal. The use of pre-emergents will go a long way to prevent this weed from becoming established.
It is best to control Cudweed in the Spring or Autumn, as it will be actively growing at these times. Due to the nature of its leaf we recommend the use of a spray adjuvant like Optispread 1000 to ensure good coverage with post emergent herbicides.
Pre-Emergent Control of Cudweed.
- Barricade or Onset 10GR
- BASF Freehand
Post Emergent Control of Cudweed.
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.)
- ProForce Weed Blast MA (Bromoxynil + MCPA)
- Contra M (MCPA + Dicamba)
- ProForce Duke
- Warhead Trio
- Nufarm Broadcide (MCPA + Dicamba + Bromoxynil)
- Dicamba
- Stature Herbicide
- Pylex
Non Selective Options.
Non selective options for Cudweed include Glyphosate (Rapid Fire 800), Numchuk Quad and Cortex Duo. If you use Glyphosate and water quality is an issue then we recommend the use of ProForce Manta Ray.
