What to do when weeds overtake your lawn?

[#1]

If you lawn has been totally overrun with weeds and there is little grass left, I would start with a clean slate and apply a weed killer to the area removing all the weeds present.

I would then follow that up by aerating the lawn and filling those holes with Bastion 20kg River Sand. This will allow a route for water to drain through.

Once you have completed the aeration, I would apply Hortico 25 Lawn Top-dress Mix and then re-seed or lay turf.

Here's a couple of helpful step-by-step videos:

• How to grow lawn from seed 
• How to lay instant turf.

You should find the advice useful in this process. - MitchellMc

If you feel that your lawn has been overtaken by weeds, it is worth starting from scratch and following Mitch's advice above.

If you have some grass left and decide to try recovery first, I recommend Yates 2.4L BuffaloPro Weed 'n' Feed Hose On Weed Killer. This is safe for buffalo and other common lawn types. I then propose an aggressive campaign of manual weed removal. It doesn't have to be all in one go: you can complete the weeding in sections as time permits.

I then propose aerating the soil and topdressing it so that you can prepare it for reseeding or patching it with instant turf. - EricL