pumpkins in pots - advice needed for novice

[beaandtig]

 
I am growing pumpkins in pots in the garden and they seem be doing very well (better than I had expected it's my first year).  Can anyone give me advice on whether or not I should nip off some of the pumpkins that are starting to grow?  I'm worried that living life in a pot will mean that they can't sustain many pumpkins and I would rather have a couple of crackers than loads of under-developed ones.

Also, in my flower bed I have some sweetcorn - when should I harvest this?

I'm very jealous of all you lot with your allotments, you're an inspiration!
:)

[beaandtig]

[Amazin]

As the sweetcorn develops, look for the changing colour of the tassle on the top. When it turns brown, go for it.