First callas are not lilies at all, despite their name :-) They are members of the Arum family.

Second, you may have some issues with the warmth of your zone inhibiting good lily ("true lily', genus Lilium) growth. They need a cold dormant period and it is suggested they be chilled each year before planting.

But......if you are willing to just accept the term "lily" as just part of the common name and not adhere to true lilies, you may very well get a serious extended bloom period.

You may need to do some research on exactly when these may bloom for you in your frost-free zone and plan accordingly. I'm not sure you will get year round bloom but with care, I bet you get a good 8-9 months. Note - some make better cut flowers than others :-)

Amazon lily, Eucharis ÃÂ grandiflora
African lily, Agapanthus africanus
Arum lily, Araceae
Belladonna lily, Amaryllis
Blackberry lily, Belamcanda
Blood lily, Haemanthus
Calla lily, Zantedeschia aethiopica
Corn lily, Veratrum
Cornish lily, Nerine bowdenii
Daylily (or Day lily), Hemerocallis
Easter lily, Lilium longiflorum
Fawn lily, Erythronium
Ginger lily, Alpinia or Hedychium
Guernsey lily, Nerine sarniensis
Kaffir lily, Schizostylis coccinea
Lent lily, the wild daffodil, Narcissus pseudonarcissus
Lily of the valley, Convallaria majalis
Natal lily, Clivia miniata
Paradise lily, Paradisea
Peruvian lily, Alstroemeria
Pineapple lily, Eucomis
Rain lily, Habranthus, Cooperia and Zephyranthes
St Bernard's lily, Anthericum liliago
St Bruno's lily, Paradisea liliastrum
Sand lily, Veltheimia capensis
Spider lily, Crinum: Hymenocallis: Lycoris
Swamp lily, Crinum pedunculatum
Water lily or waterlily, Nymphaeaceae (aquatic plants)