I have tried to kill of winter grass in my lawns. I am using "Amgrow" Winter Grass Killer from Bunnings. I am following instructions carefully but the winter grass is thriving and the lawn is dying off. I live in the South West of WA. I am at my wits end
Winter Grass Issues in My Lawn.
Certified GKH Gardening Expert
The weed can become a real problem over time as the many generations of weeds create more and more roots systems which will keep filling the soil like spiders webs. The root systems are very intensive and will eventually fill the soil to choke out the root system of the lawn itself.
The herbicide for Winter Grass is unique amongst most other herbicides, this one acts on the roots system of Winter Grass rather than on the leaf system like other poisons.
Expect to treat Winter Grass for a few years running as the seed banks will take some time to deplete their stocks in the soil.
Winter grass needs to be treated as early in it's life cycle as possible, in fact the best time to treat Winter Grass is before it is even seen. This is when the Winter Grass seeds have germinated in the soil but have yet to be emerge into the lawns surface.