Gloriosa superba is a striking climber with unusual and beautiful, red and yellow, flame-like flowers in summer; it is suitable for shade or sun, and is easy to grow.
GrowGloriosa superba in fertile, well-composted soil in a sunny, semi-shaded or lightly shaded position, and water well in spring and summer. They will tolerate poor soils, but perform better in fertile loamy soil. Allow them to scramble up through shrubs and trees or give them a string or thin-wire trellis to climb. They won’t cling to poles or chunky wooden trellises, and while they are mostly tough and easy to grow, the stems can be damaged and growth halted by attempts to train or redirect them. It is a good container plant. In winter-rainfall climates, keep them dry in winter or grow them in well-drained soil, as the dormant tubers are prone to rotting. Gloriosa superba is tender to frost and in cold climates should be planted out once all danger of frost is passed. It is also suitable for coastal gardens, even those that get salt-laden winds as it occurs naturally in coastal dunes in some areas.
Gloriosa superba can be propagated by seed or division of the tubers. Lift and divide the tubers in late winter while the plants are dormant, but just before new growth starts in spring. Handle the tubers with care as they are delicate and brittle. They are slow to increase by tuber, and should not be lifted more frequently than every three years. Sow seeds in spring. Germination is best at warm temperatures between 20º and 25ºC, but not higher. Remove the fleshy outer coat and soak the seeds in warm water overnight. Use well-drained, sterile potting soil, press them into the soil and cover lightly. Keep the trays moist but not wet. Germination is erratic, occurring in 2 weeks to 3 months, with some seeds remaining dormant for up to 9 months. Seedlings can be planted out straight into the garden or their container as soon as they are large enough to handle, or pot them up and grow them on in the nursery. Young plants grow rapidly, but a plant takes 3–4 years to flower for the first time from seed.