Only divide agapanthus after flowering. The best time to do this is in autumn.
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.
Lift the plants and carefully divide the crown with a sharp spade, making sure that each section has at least two growing points. You may need to use two garden forks back to back to divide very established clumps. This can be done in spring or after flowering in autumn.
The best time of year to cut back agapanthus is in early spring. Leaving the spent foliage over the winter can protect the crown from rot during winter rains and insulate the roots from cold temperatures. During the summer, you can help the plant conserve energy by removing spent flowers.
It is strongly recommended to never risk the survival of your agapanthus by dividing them in the summer months. Again, only divide agapanthus after flowering. The best time to do this is in autumn.
As the plants mature, they crowd against each other underground, and this overcrowding limits their flowering. The best way to remedy the problem is to start dividing and transplanting agapanthus.
Deciduous varieties – Cut back agapanthus stems to about 4 inches (10 cm.) above the ground at the end of the blooming season. However, if you like the texture and structure that spent plants provide to the winter landscape, cutting back agapanthus can wait until early spring.
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.
During autumn and winter many plants, especially perennials, can be divided. They include agapanthus, orchids, bergenias and Japanese windflowers. Use the new plants around the garden, give them to friends, or pot them up and take them along to the local fete to sell.
Plant a tall bush or blooming climber, like wisteria, that pulls the eye upward. Or you might plant dwarf agapanthus with hydrangea, and then add spiky birds of paradise, wild purple coneflowers, or Shasta daisies. Low growing alyssum or dianthus look magical along the border. Did you find this helpful?
Collect seed when the seedhead is becoming brown and the capsules are starting to burst. If the weather is turning cold you can collect seed prematurely and store the whole seedhead in a paper bag, but it's preferable to let the seed ripen on the plant.
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.
Plant 60cm apart for tall varieties, and 30cm for dwarf varieties with the plant crown at soil level. When planting in pots, root congestion is not a major concern, as Agapanthus plants tend to respond quite well to this. When the roots have too much space, leaf growth will be encouraged rather than flower production.
Established clumps can be lifted and divided into smaller clumps. Spring (late March and April) is the best time to do it.
Iron deficiency will cause the Agapanthus plant leaves to turn yellow. This is because iron is needed for making chlorophyll, the substance that gives leaves their green color. The younger leaves will be affected first. Their veins will remain green but they will begin to droop.
It is possible for Agapanthus plant leaves to turn yellow if they are over-fertilized. If too much plant food is added to the soil, the pH level will change, and the plants may find it hard to absorb the nutrients. If this occurs, the leaves of the plant will turn yellow, indicating something is wrong.
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.
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.
To restrict its spread from your garden, deadhead stalks as flowers finish and don't dump unwanted plants. If you have a mass planting of agapanthus, deadheading sounds onerous, particularly for a plant that's often grown for its low maintenance.
Although tolerant of drought and poor soil, both flower and foliage production improves with moisture and feeding. They perform best in a position in full sun or part-shade in any well-drained soil.