There's a theory that english gardens tend to look a bit miserable come midsummer because people are tempted out and into the garden centres with the first fine weather, and buy whatever is in flower then.

You can turn that round on its head: find a nurser or garden centre that you like, and make a point of visiting it at different times of the year. Then any impulse buys will have their season of interest at different times during the year.

Ideally, of course, you'll see things that you like, then you'll go home and research their needs, and only then come back and buy them. Yeah, right.