Perennial pots in winter

Just a quick one whilst I remember and before winter gets here... I have got quite a lot of pots (not too big either) with perennials in. When they have finished flowering, do I cut them down to almost nothing and also what do I do with them over,the winter? Do I have to keep them inside somewhere, like my shed, or doi just,leave them all out? Thanks.

 

I really don`t cut my herbaceous perennials down, I let them wither on top of the pot as a sort of mulch, I have tidied them up around now though , cut off dead flowers etc, I have a greenhouse so I can put the very tender in there, everything else goes against my south facing back wall, out of the wind, if you have fleece you can tuck round and anchor down great. A shed would be as good, some use garages, I would not suggest anywhere totally dark though.
Which of the plants are you trying to keep, lavender is very hardy , the fuchsia may be very tender, are those penstemon ? they are quite hardy, cosmos is an annual save seeds for next years flowers..and sunflowers.

 

They are penstemon ( I had to google that!) there are also hot Lips ( not sure of Latin name) and the fuchsia. The photo with the pink spiked flowers and the yellow ones ( I should know there names!) are also perennials. I have got a shed so will put them in there. I take it I still need to water them throughout the winter? And then top dress in spring as new growth starts to appear? Thanks formthemadvice so far. Cosmos has definitely been one of my ( and the bees) favourite this year...shame they won't come back..but I will attempt (somehow) to get some seeds....

 

Cosmos is a brilliant all rounder, let 2 or 3 of the flowers go to set seeds, when they look really brown take the flower heads into an old envelope/ paper bag, leave somewhere to dry, the seeds look like this. http://theseedsite.co.uk/profile272.html.

no you do not water in the winter the plant is resting, hot lips is a salvia theres a section devoted to salvias may help you.

 

Thanks very much :-)