Mirabilis longiflora, Sweet Four O'Clock, is a fast-growing perennial from the American southwest and northern Mexico with extraordinary night-blooming flowers that have an elongated curved tube that can get as long as 18-25cm. The sweetly fragrant flowers are smallish and white with a maroon patch on their inner throat and yellow anthers. They open in the cool of the evening and close again in the heat of the morning sun.

It prefers full sun and although it is capable of going for long periods without water it should be well watered throughout the summer which will encourage its rapid growth and create a lush-looking plant. A herbaceous perennial, it develops tough tuberous roots and after the leaves have been hit by the first frosts it is these roots that survive through the winter, the foliage growing again in the late spring/early summer.

An easy low-maintenance plant that is showy and different and works well with other flowering exotics.