It can take from a week to a fortnight to germinate, here
The weather forecast looks as if we're all going to get some rain over the next week or so, so you shouldn't have to water it. Colder nights mean the soil gets damp at this time of year as well.
I don't ever dig mine in, I find a good hard frost kills the top growth so the roots just rot in situ leaving drainage channels for winter rain, and softened soil by spring, ready for gentle work over with the 3 pronged cultivator
If you don't get hard killing frosts where you are, I'd strim it down in early spring and leave it for the worms.
It shouldn't try to flower sown at this time of year, mine never has...