As for what to plant, stick to the tough, reliable types that will overwinter easily: perennials such as anemones, sedums, echinops (Echinops ritro is a beast – just a warning), aquilegias, Rudbeckia fulgida and its like, heucheras, Brunnera macrophylla, geraniums, geums and Knautia macedonica are made for autumn planting.