I know a lady who looked after her son's "plants" while he was on holiday, she was told they were tomatoes.
To get back to the question, anything you need to keep frost free. Small plug plants of begonias etc. to pot on. Much cheaper to buy this way, I got 70 for £17.99, can pay £2.99 each for full size ones in the garden centre. Try Gardening Direct online. My begonias in pots were beautiful last year, I don't do flower beds, all that weeding.