Sandersonia is a genus with a single species, Sandersonia aurantiaca, that is a member of the Colchicaceae family and endemic to South Africa. It grows in damp grassland, on forests margins in the eastern areas of South Africa. Referred to as Christmas bells since that is when it blooms in the southern hemisphere or Chinese Lantern because of the orange flowers, this has become a popular flower for the cut flower business and many are grown in New Zealand.
Sandersonia aurantiaca seeds must be stratified before planting. Soak the seeds in water overnight. The next day put the swollen seeds into a plastic bag and put in the fridge for 3 to 4 months. Open the bag each month and check that the seeds are still moist, and if not, moisten them slightly. At the end of 3 months, sow the seeds normally in well drained potting soil - this should be in late spring when the weather is warm. The seeds should germinate in about 4 to 6 weeks. Keep the seedlings growing through the summer and they will go dormant in late summer or autumn. Do not throw the soil away - more seeds will germinate the next year, and perhaps the year after that too (Rachel Saunders). Joyce Miller finds that a plastic pot covered with glass placed under lights and on a heating mat gives good results.
Plants are extremely susceptible to a whole range of diseases which make them rot in damp humid conditions. Growers are advised to lift them every year and replant them into sterile soil. Another option is to use fungicide. Plants can be brought into flower at different times than the normal summer flowering by allowing them to go dormant and then watering several months before you want them to bloom. Plant the tubers in a deep container and give the plant something to climb on.
Here is a picture of Sandersonia growing in the wild, where it was thriving near a mountain stream in the foothills of the Drakensberg. Several dozen plants were in a colony spread over 100 square meters. Photo taken by Roy Herold at Giant's Castle, KwaZulu-Natal Province, in December, 2006.
The photos below are of plants in cultivation. Photos 1-3 are of plants grown in a greenhouse in coastal Northern California, kept dry in winter and getting extra heat and regular water in summer. Photo 1 was taken by Bob Rutemoeller. Photos 2-3 taken by Mary Sue Ittner show plants in bloom in July 2005 and a blooming rhizome with smaller offsets as the rhizome starts into growth in the spring. The rhizome is on a grid of 1 cm squares. Photos 4-5 were taken by Nhu Nguyen.