Hi there Guest,

It depends what you mean by "Calla Lilies".

There is only one species of Calla and that is Calla palustris, a slightly low-key aquatic Aroid (member of the Arum family).

If you're looking for the large, pure white-flowered, hardy "Arum Lily" that is widely used in Floristry etc., then that is Zandedeschia aethiopica, which is available at most decent garden centres and a wide variety of nurseries.

There is also Zantedeschia elliottiana which is bright yellow and Zantedeschia rehmannii which is pink flowered, but neither of these two are garden hardy in the UK.

Finally there are a wide array of different coloured Zantedeschia hybrids that range from yellow through reds peaches, pink to near black. They are commonly seen in floristry and are also sold as house plants and summer colour for the garden. These are not hardy in this country, although it's easy to care for them through the winter and start them off again the following year.

Google each of the names and decide which is one that you're looking for.

Local & mail-order suppliers for all of these plants can be found using the RHS Online Plantfinder:

http://apps.rhs.org.uk/rhsplantfinder