A monster, and it is sold as one. From a February sowing it makes a 1.5m plant by June, with a great rosette of paddle-shaped leaves at the base and a central spike carrying dozens of long hanging white trumpets. By day it is architecture rather than flowers; the trumpets stay shut against the heat and what you have looks distinctly tropical.
Then the temperature drops in the late afternoon, the trumpets open, and the scent arrives. It is the strongest evening fragrance in the garden, and combined with the scale and the white catching the last of the light, it is the reason people build moon gardens.
Be realistic about the space. It needs the back of a large border and 60cm of clear ground around it, and the central spike wants staking in anything exposed. It also needs rich, moist, fertile soil and regular watering. This is not a drought-tolerant plant; starve it and you get a third of the size. Plant out in June, not before. The leaves are sticky and catch small insects, which is defence rather than digestion.
