Peter Dowdall: Why I associate August with hydrangeas, sweet peas and asters

'One of my mother’s favourite flowers was sweet pea and each year I grow them and think of her,' says Peter Dowdall. File pictures
There's one very important thing to do in the garden during August. It’s important because, whether we like it or not, summer is drawing to a close, the evenings are getting that bit shorter — perhaps not yet too noticeable but shorter they are getting — and soon life will head even more indoors.