Calla Lily Spectrum Mixed Add some glamour and shine into your garden with this magnificent collection of half-hardy Calla Lilies! The vibrantly coloured spathes are set against a backdrop of sumptuous, silver-spotted, heart-shaped leaves. These exotic-looking Calla Lillies are perfect for long-lasting cut flower arrangements. Over-winter the rhizhomes in a warm, dry place and you can enjoy them year after year. Bulb size 12/14. Height: 60cm (24). Spread: 20cm (8).