In the dog days of summer, when nothing can grow, the women of ancient Athens fashioned these little gardens in baskets and pots. Each held a mix of quick-sprouting grain and herbs. The makeshift seedbeds were carried up ladders on to the flat roofs of private houses and left to wilt in the sun: a botanical re-enactment of the premature death of Adonis, the fallen hunter, slain in his prime by a wild boar.