"Dave" none wrote in message
...
My hollyhocks are coming to the end of their flowering, and jolly nice
they
were too.

Do I just leave them to wither away or should I cut them back come autumn?

I leave them for a few weeks, then collect the seed. Else you can cut the
flower spike whenever you like.

HTH

Cheers

Nick
http://www.ukgardening.co.uk