I observed at a number of project sites that these annuals succeed other herbaceous weeds after those were removed from under trees and drainage lines. I trial broadcasting Weeping grass directly over chickweed at various sites such as paddock; the idea is that perennial grass establishes and out-competes the weak annual Chickweed. Unfortunately, we head into dry and hot season so I'm not sure whether it is not too late to broadcast seeds.
I sprayed all along lower part of gully up to the line of A. mearnsii but not this clump; may be someone can manually remove if not too many? no need to bag at this stage as they haven't developed fruits. I will map what I've sprayed on Sat 19 Sept after the mulching work party.