Glyphosate takes a few weeks to work and might even need repeat applications.

I'm desperately trying to get rid of clumps of dandelions and they're taking an age to go, i've used the same stuff but no signs of death yet !

Repeated spraying and elbow grease too at first. I would dig out as much as I can and then spray any young growth as soon as it reappears, which it will. But have a look at my profile page where I describe what worked for me with ground elder.

What worked for me with ground elder was elbow grease and persistence - spray with glyphosate, wait a week to ten days, spray again, wait another week and dig, dig, dig, lifting out all plants and roots as you go. The glyphosate appears to kill off the fine, hairlike roots, which make it impossible to dig out without treating it first, leaving the larger, thicker ones for you to dig out. As for the bluebells, digging again, I've never found any weedkiller gets rid of them, well, not one you can use somewhere you ever want to grow anything else.

THank you - I suspected Glyphosate was not enough but I'll give it a second spray and see how we go. I actually quite enjoy the elbow grease - its just that its a pretty big plot!
And thank you too inverglen - I love perennial geraniums - I'll track some of these down

For perennial geraniums try Long Acre Plants - I just had four from them by return of post,nice plants, good condition and well packed.