How to plant zantedeschia (calla lilies)
Commonly known as calla lilies or arum lilies, zantedeschia are exotic and elegant plants native to South Africa bearing beautiful waxy spathes held above lush long green leaves adorned with a fluted edge. Whether they are grown as marginal aquatics, in the garden border or in a container, these tough and robust beauties will grace your garden with years of colour and will provide you with excellent long-lasting cut flowers. Depending on the area where you choose to plant them, their foliage can be semi-evergreen to evergreen.
Zantedeschia will thrive in fertile, humus rich, moist, well-drained soil benefitting from partial shade or full sun. If planting as a marginal plant, make sure to use aquatic compost. On the other hand, if planting in pots, use John Innes Compost № 2 as it is ideal for plants grown in containers. Plant your corm just below the surface and feed every couple of weeks with high potash feed. If you garden organically, liquid seaweed is ideal as it is organic and comes from a sustainable source. In late autumn, provide your zantedeschia with a good mulch of organic matter around the base. In the winter, cut away any frost damaged leaves and give protection to the crown; you can cover it with straw or a deep mulch of bark chippings.
Always wear gloves when handling your zantedeschia since they can cause skin irritation. All parts of the plant are highly toxic to humans, dogs, cats and should not be eaten.
Always unpack corms on arrival and store in a cool place until ready to plant.
Potential problems, pests and diseases:
- Aphids: these insects will spread viruses and diseases and will weaken the plants.
- Thrips: these microscopic insects will suck the gladioli's sap, causing the leaves to fleck with white and later preventing the flower bulbs to open. As soon as you notice any signs of this, cut back all the foliage and destroy. Both organic and non organic sprays will be able to help control the attack.
- Fungal and calla lily rot: dig out and destroy all parts of the plant and bulb.