How to grow sweetpeas

I am writing this knowing it isn't the sort of thing that I would usually post. However it is the sort of post I have often looked for and it is also a nice place for me to out all the knowledge that I have got from years of growing sweet peas so that I don't forget it either!

The best wisteria spots near to the Wirral

This is a funny sort of niche post but it's one I might quite like to read so I figured I'd go ahead and post it anyway.