Look at the base of the plant, and if you can see new growth, then it's fine to cut the stems back right to the bottom when they look 'tatty' and start going brown. I've cut back one of my plants so far. The other one still has a couple of flowers.

which plant is Broadway lights?

Ha ha, seaburngirl, that's why I clicked on this, I've no idea what Broadway lights are either...

I think they are a shasta daisy!

thanks spritzhenry :) yes they are shasta daisy the man at the flower show was selling them as broadway lights so I just googled it and they are :) lol thank goodness for google ay!!!

Sorry - I should have said what they are! They're a creamy-yellow flowered Leucanthemum (Shasta Daisy).

Very pretty too. :-)) Yes, I google things all the time...very useful! lol.

I have this plant Leucanthemum 'Broadway lights' and I cut mine back last week to about 3" as it has not been such a good year for it. Its about 4 years old so I will divide it this year.

thanks Dcr..I will do the same :)