Parramatta Grass (Sporobolus africanus).
After you finish reading this, you will be able to:
- Identify Parramatta Grass or Rat’s Tail.
- Know what conditions favour Parramatta Grass.
- Know the best cultural and chemical options to control Parramatta Grass or Tussock Grass.
Rat’s Tail is spread rapidly by vehicle traffic, wind and flood water. It grows rapidly, is frost and drought resistant, and produces approximately 80,000 seeds per plant.
- Is a weed in wet areas such as over watered turf, roadsides and waste areas.
- It emerges all year round when soil moisture and temperatures are suitable. Spring and Summer is when most seedlings appear.
- Produces large quantities of seed that readily disperse, and the soil seed bank can build up quickly. Seeds are viable for a long time.
- Tussock Grass grows in lower rainfall, but is most common in areas with an average annual rainfall above 700 mm per year.
More information on common lawn weeds is in our weed ID chart. What they reveal about soil conditions is in our blog on indicator weeds. Rat’s Tail is an Indication of soil compaction.
How to Identify Parramatta Grass.
Category: Grass
Flower: The flowers are green or grey.
Height: Stems grow up to 50cm in height.
Leaf length: The leaves are up to 20 cm long.
Leaf width: The leaves are up to 6 mm wide
Reproduction: Seeds are spread in soil on machinery and vehicles. The seeds become sticky when wet, and then stick to animals and clothing. Rat’s Tail produces up to 60,000 seeds per square metre, and estimates of the soil seed bank have put it at up to 600-4,000 seeds/m2.
Parramatta Grass does not disperse by wind, and even though the seed is small, most seed falls within 2 to 3 m of the seeding plant.
Comments: Rat’s Tail has very tough, smooth and glabrous, dark green leaves. These are mainly around the base, and are slender and stiff, with in-rolled margins. Where the blade meets the stem, the leaf sheath is rolls around the stem.
Habitat: Parramatta Grass mostly grows in areas with a moderate to high rainfall. It favours compact soils, and will invade low maintenance turf areas.
How to remove Parramatta Grass from your lawn.
Cultural control.
Preventing the spread of Parramatta Grass seed is the most effective way to control this weed.
Daily fluctuations in temperature, and exposure to light stimulate germination of this weed. This means that maintaining a full turf cover reduces these fluctuations, and helps prevent germination. Any bare areas or thin turf will increase seed germination.
You can control Parramatta Grass by hand removing small plants if there are not too many. However, you must bag the seed head first to prevent seed dispersal. Slashing or Whipper snipping before you use a herbicide can also pay dividends.
The key is to try to manage this before it seeds.
- Dig out the plant, and try to minimize soil disturbance.
- Immediately place the entire plant in a sealed bag. Remove this off site asap.
- Regularly re-check the site for new plants.
As it favours compact soils, soil aeration can also help manage this. Also, bare in mind that keeping N up to your turfgrass helps deter this weed, as it encourage a healthy turf cover.
Chemical control.
