Daffodil question.

Last autumn I planted daffodils along the grass verges down the lane where we live. They came up fantastically but are nearly done now. I have been cutting the heads off the dead ones as they have died. I also mow these grass verges every weekend to keep the lane looking nice and tidy.

Now my plan is at some point just to mow the whole lot and therefore loose the stems and the rest of the plant leaving just the bulbs in the ground ready for next spring.

My question is when do I do this ? Should I have done it already ? There are still one or two still flowering which is why I have mowed round them but in reality I think they are all but done.

Thanks !