Plant Guide: Agapanthus

African lilies (Agapanthus) are perennial plants valued for their striking, spherical flower heads made up of bright blue or white, trumpet-shaped flowers. The deep green, strap-shaped leaves form a rosette, from which strong flower stems emerge in mid-summer. In cooler climates, most Agapanthus are best grown in containers so they can be placed outdoors during summer and moved to a sheltered location for winter protection. The commonly grown ‘Headbourne’ hybrids are deciduous, fairly hardy plants that reach a height of around 60 to 120 centimetres.

How to plant

Agapanthus is planted in late spring, with the fleshy roots set about 10 to 15 centimetres deep in the soil. The roots should not be allowed to dry out before planting. A well-drained, fertile soil rich in organic matter is essential for healthy growth. When growing in containers, a loam-based potting compost enriched with additional organic material is recommended. Choose a sunny, sheltered position, as exposure to cold winds can reduce flowering.

Flowering period

The flowering period begins from mid-summer, when large, decorative flower heads rise above the foliage. During this time, the soil should be kept consistently moist but never waterlogged. Container-grown plants require regular watering and benefit from liquid feeding every two weeks throughout the growing season. Although the flower stems can be cut once the lowest flowers have opened, they are most attractive when left on the plant.

After flowering

After flowering, the foliage of deciduous types is allowed to die back naturally. During winter, the rosette can be protected with a layer of straw, or container plants can be moved to a frost-free greenhouse or conservatory in colder regions. This winter rest helps ensure strong growth and flowering in the following season.

Tip:
Agapanthus flowers best when slightly pot-bound and grown in full sun. Too much space or insufficient light can result in lush foliage but fewer flowers.