Khaki Weed (Alternanthera pungens).
Khaki Weed is also known as Creeping Chaff weed. It is a creeping perennial herb with a deep taproot and spiny burrs. These injure people and animals, and cause hay fever, asthma and skin redness and swelling. Khaki Weed is a declared weed in VIC, NT and SA.
After you read this, you will be able to:
1. Identify Khaki Weed in your lawn or turf area.
2. Know what conditions favour its establishment and growth.
3. Know how to control this weed.
How to Identify Khaki Weed.
Flower: Chaff Weed has unobtrusive cream-coloured flowers. These have an oval shape and hairs with barbs at their base. The fruit is a chaff-coloured prickly burr about 1cm long.
Height: Low growing/prostrate.
Leaf length: The leaves of khaki weed are 4-5 cm long.
Leaf width: The leaf width is 1 cm wide, and the leaves do not have stalks.
Comments: The roots form at the nodes of the stems. The stems are prostrate, have a reddish colour, and can be up to 60 cm long. Under a microscope, these stems have fine teeth and soft silky hairs. The leaves have prominent veins on their underside. Khakiweed produces a deep taproot used to store carbohydrates for emergence and growth in subsequent years.
Habitat: Creeping Chaff weed is widespread in waste areas, caravan parks, and playing fields.
Height: Low growing/prostrate.
Leaf length: The leaves of khaki weed are 4-5 cm long.
Leaf width: The leaf width is 1 cm wide, and the leaves do not have stalks.
Comments: The roots form at the nodes of the stems. The stems are prostrate, have a reddish colour, and can be up to 60 cm long. Under a microscope, these stems have fine teeth and soft silky hairs. The leaves have prominent veins on their underside. Khakiweed produces a deep taproot used to store carbohydrates for emergence and growth in subsequent years.
Habitat: Creeping Chaff weed is widespread in waste areas, caravan parks, and playing fields.
Khaki weed is a strong indicator of light, high moisture soils over the spring and summer, and is included in our weed ID Chart.
Khaki Weed grows from roots and seeds, so to get the best results treat it before it seeds.
How to Control Creeping Chaff weed.
Cultural and chemical control will control Khaki Weed in your lawn and turf.
Cultural control of Khaki Weed.
Practice good hygiene if you are using machinery in infected areas. Hand removal works as long as you remove the crown and the taproot, and make sure that you remove all root material. If you break the tap root of Khaki Weed when you remove it, new plants will grow from any material left in the soil. Aim to dig down 100 mm or more beside the root. Remove and destroy any burrs found.
Chemical control of Khaki Weed.
It is best to apply post-emergents when the weed is growing strongly and not under stress. If you can target seedlings, these are the most susceptible to chemical treatment. The aim is to reapply treatments consistently until you eradicate the Khaki Weed. Several herbicides control Creeping Chaff weed in turf and lawns. Gilba Solutions recommends that you use Casper or 2,4-D Amine for selective control.