Arum lily or Calla Lily called Zantedeschia are available in an increasing number of shades and varieties. This Zantedeschia rehmannii can be grown to advantage in a terracotta pot that will show off the perfect spathes or funnel shaped petals.
- Arum Lily is the common name for the hardier outdoor variety. Usually white or pink.
- Calla Lilys are often the less hardy but colourful varieties in white, yellow, pink, red or purple and are easy to grow from bulbs.
- Zantedeschia have heart shaped leaves often with decorative spots.
- Zantedeschia will flower for long periods throughout the summer with dramatic and exotic shaped flowers.
- They are not frost hardy so they should not be planted out until after the end of May in the border or pots. I bury the pots to fill odd gaps and can easily bring them indoors in winter.
- Grow them in one and a half litre pots with loam-based compost such as John Innes No 2 and plant the rhizomes just showing at the surface of the container with the eyes of the rhizome uppermost.
- Water freely through the summer and feed with a balanced liquid fertiliser every two weeks until the flowers have faded.
- They make exotic houseplants as well as summer border or container plants.
Zantedeschia originate from Africa and plantzafrica give this and further information
‘This is an old fashioned, but very rewarding garden plant. Zantedeschia is named after Professor Zantedeschi, probably Giovanni Zantedeschi, 1773-1846, an Italian physician and botanist, although there is some uncertainty about this. Although called the arum lily, it is neither an arum ( the genus Arum) nor a lily ( genus Lilium). But it is associated with the lily as a symbol of purity and these elegant flowers have graced many bridal bouquets.
It is an excellent cutflower and lasts a long time in water. Nowadays there are other forms of this species which will enliven an old theme. The ‘Marshmallow’ with a creamy pink spathe (outer “petal” which is actually a modified leaf) and rose-pink throat and the ‘Green Goddess’with a green and white spathe. There is also an attractive form with leaves spotted white.
This lovely plant was introduced to Europe very early on, apparently before Van Riebeeck had established the refreshment station at the Cape. It is also illustrated in an account of the Royal Garden in Paris in 1664. It was sent as one of the interesting plants of the Cape to Europe by Simon van der Stel some time before 1697.
The striking arum lily “flower” is actually many tiny flowers arranged in a complex spiral pattern on the central column (spadix). The tiny flowers are arranged in male and female zones on the spadix. The top 7 cm are male flowers and the lower 1.8 cm are female. If you look through a hand-lens you may see the stringy pollen emerging from the male flowers which consist largely of anthers. The female flowers have an ovary with a short stalk above it, which is the style (where the pollen is received). The spadix is surrounded by the white or coloured spathe. According to Marloth, the whiteness of the spathe is not caused by pigmentation, but is an optical effect produced by numerous airspaces beneath the epidermis.
The flowers are faintly scented and this attracts various crawling insects and bees which are responsible for pollinating the flowers. Cross pollination occurs as the anthers of each flower ripen before the ovaries. A white crab spider of the family Thomisidae visits the flower to eat the insects. This spider does not spin webs and uses its whiteness as camouflage against the spathe. In the western Cape, a tiny frog Hyperolius hopstocki is also attacted to the arum lily flowers. The spathe turns green after flowering and covers the ripening berries. It rots away when these are ripe and the succulent yellow berries attract birds, which are responsible for seed dispersal.
The genus is restricted to the African continent with seven species recognised: Zantedeschia aethiopica, Z. albomaculata, Z. elliottiana, Z. jucunda, Z. odoratum, Z. pentlandii and Z. rehmannii….’