Hi @3jidaddy,
It looks like you have Kikuyu grass growing up through Couch grass. Mixed grasses like this are common and there's no real issue with leaving them be as long as you are happy to do so.
The reality is, over time, the dominant grass will eventually take over the space and it is more than likely this will be the Kikuyu as it is far more aggressive than almost every other type of lawn grass.
Luckily, Kikuyu actually looks really nice and makes a wonderful lawn that is hardy, drought tolerant and will stay green through Summer with minimal watering.
Manually pulling it out can work for a while, but it’s labour-intensive and often ineffective as kikuyu spreads through underground runners and seeds.
Outside of removing the top 300mm of soil, replacing it with fresh new soil and planting new grass, there's not a lot you can do to decisively get rid of Kikuyu.
Unless you take drastic measures, it is more than likely there to stay, but as I said, it's actually a nice grass, so this isn't really an issue.
Let me know what you think.
Jacob
