Seed pods should be harvested when they have begun to split open, but before the seed begins to drop from the pods. Pods should be picked and stored dry until the seed can be threshed. Threshed seed is best stored in airtight containers in a cool, dry environment. One thousand seeds weigh about 7g. Sandersonia seeds have a deep dormancy mechanism, and require chilling and leaching to overcome this.
Growers use a range of seed treatments to overcome dormancy.
However, germination rates are variable between these methods and between seasons. Some growers sow the seed outdoors in beds or in trays where the seed receives chilling and leaching, while others in districts with cold winters hold the seed in sacks outdoors and then sow the seed in the spring. When seeds are sown in the field, light soils with good drainage are preferable as tubers are difficult to lift on heavy soils and tuber shape is more variable. Tubers of 1g-2g size are generally produced in the first season from seed. From tubers The other method of tuber multiplication is to produce a new forked tuber from each growing point, and thus double numbers each year.