Reading Rob's comment about Melianthus major smelling of peanut butter has got me…
They will tolerate the cold, and will grow well in well drained soil, they prefer full sun and dislike dry conditions. Prune in late summer. Once it is established (in native areas), it will need no water.
You can propagate from seeds or cuttings in winter.
Pests, diseases or disorders
Honey fungus may be a problem; young plants are more susceptible.