Sorry about the delay, Kat! I've been trying (and failing) to find the variety name of the Arum Lily that is hardiest. Oh, well, for general info, Arum Lilies (Zantedeschia aethiopica) do best with bright to dappled shade, rich soil, and lots of moisture. In their native east African highlands, they are seasonal bog plants. Most kinds are too frost tender to be permanent plants in most of the British Isles....Aha! I finally found the name of the hardiest kind: Z. a. 'Crowborough'! So, that kind would be the safest kind for landscaping use, unless you are in the mildest parts of the southwest. Otherwise, grow them in pots, plunge them into the garden--or display on the porch--in the summer, and keep them in a frost-free area over the winter. The colored forms of Arum Lilies need more light, better drainage, and even less frost than the white Z. aethiopica.