The Zantedeschia Arum lily, Calla lily. Very exotic looking perennial from South Africa growing from rhizomes up to 1m tall with a 35-45cm spread, though forming large clumps with time. It has lush and lustrous dark green leaves that are arrow-shaped up to30cm (1ft) long. The pure white inflorescences (flowers) are from 10-15cm (4-6in) long appearing spring and onwards into summer, with the odd flower at any time. In the wild it forms colonies in marshy areas. Zantedeschia aethiopica ‘Crowborough’ is one of the most commonly available to buy and is identical to the species, but with greater hardiness in cooler temperatures like ours here in the UK.
‘Green Goddess’ is a fabulous form bearing a succession of green spathes, (flowers) each with a large radiating central splash of white and also grows up to 1m tall.
Zantedeschia elliottiana or ‘Golden arum lily’ is another beautiful species, growing from 60cm- to 1m with semi-erect basal leaves with random and very conspicuous transparent markings. Although usually considered half-hardy in England, they have overwintered without protection in my Norwich garden for more than a decade with lows of-10°C, (though they do not always flower).
There is a large range of Zantedeschias, referred to in the trade as callas, in a dazzling array of exciting colours, which add greatly to the exotic garden. Many of the new hybrids coming onto the market were created through crossing many of the smaller species.
A form available in the US named Zantedeschia aethiopica gigantea is ridiculously large, growing to 1.5m or more with huge leaves up to 45cm long with large flowers up to 25cm long and will become an absolute must for the exotic garden in the years to come…