I have just been given a seed of Ferraris crispa. Should I scarify the seed before planting or take any other special steps?
They should seed pretty prolifically, but germination rate is not great. What does germinate will germinate quite readily. You can soak them for 1 or 2 days, but that is just to help them germinate faster. It is worth noting that they will be quite slow to germinate.
They can take several weeks. This article will help you with their care:
https://www.gardeningknowhow.com/ornamental/flowers/starfish-iris/growing-starfish-iris-plants.htm