Deciduous species are best split in spring, just as the growing tips begin to show. The evergreen species should be split in autumn after flowering. When clumps are split, each section must have a strong growing shoot, which will guarantee success. Plants should then be left undisturbed for so long as they are flowering well. Unless gathered in the wild seed is unlikely to come true.
Plants raised from seed can, however, result in exciting new varieties.
Seed should be sown as fresh as possible in trays or open beds in a frost-free environment. Sow in a well-drained mix and lightly cover the seed ensuring that it never dries out. Seed sown plants will flower within two to four years. Agapanthus plants have few pests. Occasionally thrips, red spider, mealy bugs, gall midge flies, snout beetles or caterpillars may attack them.