The yellow tower cactus starts life as a golden, globe-shaped ball and slowly stretches into an upright column densely covered in soft yellow spines, glowing like a torch in a sunny window. With age and good light, mature plants open silky yellow flowers at the crown.

Full sun is its preference: a south-facing sill, or a bright porch in summer. Pot it in a gritty cactus mix and water only when the soil is completely dry, hardly at all in winter. Protect it from frost and it will grow with you for years.