Plant of the week: Morning glory

These twining annuals always bring a splash of colour

You know summer has arrived when the vibrant blooms of morning glory, or ipomoea, trumpet their presence. These half hardy plants, a mix of twining annual and tender perennial climbers, are usually grown for summer display and discarded after flowering. Rapid growing, they soon cover a tepee of canes, or grow over an arbour clothed in blooms from mid-summer through to autumn, with only pure yellow forming the rarest colour. Each flower lasts just a day, or in the case of the moonflower, I. alba, just a night, but are replaced with a succession of blooms through to autumn.

The vines are clothed in heart-shaped, or lobed foliage, with Victorian hybrid I. sloteri having the most intricately shaped leaves, ideal for smaller spaces. They do well in warm, sunny summers but can also be grown indoors in a conservatory, with the more delicately bloomed varieties from Japan, such as I. nil ‘Chocolate’ doing better in such conditions, but keep a watch out for attacks by red spider mite.

Morning glories are easily grown from seed sown in spring, under glass at a temperature of 20C (68F). Pot seedlings on, train up short canes and gradually harden off before planting outdoors after late frost has passed in June. Seed coats can be hard so chip with a knife or soak seed in warm water overnight before sowing. They like moist, welldrained, rich soil in full sun, in a sheltered position. Pinch out growth when they’ve reached

their desired height and remove spent flowers as they form.