Act quick on winter grass, for better results!
As we transition into late autumn and early winter, a range of winter grasses and broadleaf weeds begin to germinate in pastures. Among these is Poa annua, commonly known as winter grass, a weed that can have a significant impact on pasture quality and productivity if not managed early.
Recognising winter grass (poa annua)
Winter grass is easily identified by its light green color, tufted growth habit, and its tendency to seed prolifically. Poa annua matures quickly, typically seeding from late winter through to early summer. This rapid life cycle and extensive seed production allow it to spread aggressively, making it challenging to control once it has established itself in pastures.
Why Winter Grass is Problematic for Perennial Pastures
Winter grass competes directly with desirable pasture species such as ryegrass, crowding them out and reducing their access to vital nutrients, water, and sunlight.
The weed’s dense growth habit can lead to a choking effect, where it covers the soil surface, stifling the growth of productive species. This reduces pasture density and quality, affecting overall productivity and ultimately impacting feed quality for grazing livestock.
Grazing or mowing, while useful in managing some types of weeds, is generally ineffective for controlling winter grass. These methods rarely reach the root of the problem, as Poa annua rebounds quickly, continuing its growth and spreading seeds. Without a focused control approach, pastures can rapidly become overrun, leading to lower-quality forage and diminished yields long term.
We strongly advise using pre emergent chemicals such as Ethofumesate 500 if you believe you'll have winter grass issues in your newly sown perennial pasture. More on key steps below
Key steps to prevent winter grass in new sown pasture
Summer renovation: Optional summer crop with turnips or brassica, using a a pre emergent chemical Trifluralin to reduce summer grass germination
Pre emergent chemical application to create barrier in the soil, preventing the seeds from germination. Using 3-4L per hectare of Ethofumesate. Spray before the first Autumn rain.
Post emergent control options. Seek our professional help, as its important to control extremely quickly after germination.
Improve pasture density: Maintain thick, healthy pasture throughout the year to create canopy for unwanted winter grass and weeds to establish.
Winter grass spray demonstration
Using Scanner 500 herbicide, we demonstrated its effectiveness on winter grasses at Cropmark Seeds research extension site at Lardner in West Gippsland.
As you can see in the images below, there was a greater ryegrass plant population in the plots with Scanner 500 @ 3L per hectare used (left below) compared to the no spray application plots (right below) which were impacted by Poa Annual.
The images such the plots at various times over the year.
Scanner 500 can be used with broadleaf weed control. As always if you are wanting to know more winter grass control give us a call (03) 5659 2314 in Gippsland or (03) 5562 2115 in the Western District.
