Deciduous plant foliage will die back and should be cut off after it is yellow. Wait until it dies back, however, to allow the plant time to gather solar energy to refuel the next season's bloom.
The top of the plant will die back in a light frost, but the thick, fleshy roots will retain vitality and re-sprout in spring.
Agapanthus are perennials which means they come back each year. Most are hardy, and their leaves will die back each winter before returning in the spring. Evergreen types tend to be more tender, so will need some protection in the winter and early spring.
Agapanthus plants benefit from regular deadheading, which helps them conserve energy. Simply remove the entire flower stem once the blooms have faded.
“Agapanthus stems can be pruned at ground level when the flower has gone over unless you want to leave them in the garden for winter structure,” says Patrick Fairweather, the Managing Director of Fairweather's Nursery.
It is naturally disappointing when agapanthus don't flower well. It's quite a common problem, however, and thankfully one that can be resolved. To ensure a good display next year, keep plants well-watered through summer until early autumn, which will encourage the development of new flower buds.
With proper care, agapanthus flowering occurs repeatedly for several weeks throughout the season, then this perennial powerhouse returns to put on another show the next year.
Agapanthus pruning is also essential to encourage healthy growth. You can do this after the flowering season, cutting back the stems to around 10 cm above ground level for deciduous varieties, which include Agapanthus Melbourne, Agapanthus Galaxy White, and Agapanthus Little Galaxy.
Agapanthus grows and spreads by fleshy rhizomes that act as storage roots. The plant retains nutrients in its roots and may be divided to create more plants. Use a sharp shovel to dig up an established plant and divide it into several sections, each with roots and foliage.
RESIDENTS growing agapanthus plants are urged to take to their gardens and remove the seed heads before they open and release their potentially invasive seeds.
Repeat flowering Agapanthus for up to 6 months of the year.
These gorgeous plants produce masses of bright and colourful flowers in spring and summer, as well as sporadically throughout the year, including in mild winters as seen in 2020.
Dividing and transplanting in the garden
The best time to do this is in autumn. To make the plants easier to handle for lifting and division, cut the foliage back and dig around the perimeter of the plant keeping the spade or gardening fork at least 140mm out from the plant basal area and to a depth of about 200mm.
This will depend on how they're planted. If they're planted in the ground, expect to divide them roughly every 4-5 years. If they're planted in a pot that's smaller than their mature width, expect to divide them about every 2-3 years.
Most Agapanthus bloom for around 6 weeks, however 'Flower of Love' has been specially bred to be much more floriferous than other varieties, for an incredible 10-12 weeks, starting around mid-July.
Agapanthus are drought tolerant an store water in their roots. Over watering can cause root oedema and collapse as oxygen levels are depleted in the soil. over fertilising. Fertilising in excess of recommendations can cause roots to burn off and die.
You can simply open the pods and pick out the seeds. You can collect a number of pods to process by rubbing them gently between your hands so that all the seeds fall out, or you can place pale brown pods in a paper bag and place them in a dry location until they split open and the seeds fall out.
Agapanthus thrive in full sun and need 6-8 hours of sunlight each day. However, they do better in partial shade in hot climate areas. Agapanthus perform best in fertile, moist and well-drained soil. They show no preference for pH, except Agapanthus africanus which prefers an acid soil.
Agapanthus gall midge is a fly that can cause buds of Agapanthus to become deformed and discoloured and fail to flower. It was first noticed in the UK in 2014 but may have been present for several years.
Plant in full sun – agapanthus require direct sunlight for at least two-thirds of the day. Too much shade and the flower stems will become weak and extended, if they appear at all.
Feeding – Agapanthus are quite hungry feeders. For best results apply a top dressing of our Agapanthus Plant Food to the surface of the soil. It is best applied first in March, then repeated in May and August.
The best time to divide agapanthus is late March to April, before the flowering season. Lift the plant out of the ground and split the root clump with a sharp spade or two forks back-to-back, making sure each of the new clumps has at least two growing points. Then simply plant these out as usual.