Propagation by Seed
One of my books claims that 'propagating agapanthus by seed is very often unsuccessful'. It depends how 'unsuccessful' is interpreted: if I expect the seedlings to be exact copies of the parent plant, then propagation by seed is 'unsuccessful'. Bees are crossfertilising the various species, and help create new colours or revert to a wild forbear.
Seeds germinate easily and are very fertile. The first seedlings appear usually after 3 to 4 weeks, in rare cases it takes up to 2 to 3 months.
It is necessary to select the plants which should be cultivated any further. The number of seeds in an agapanthus flower varies. One species may yield 3 to 5 seeds per individual flower, others more than ten. Although the amount per individual flower appears small, the yield per umbel flower is considerable.
Sowing agapanthus seed is especially fascinating for the hobby gardener: both shape and shade of the seedlings are quite a surprise. On the other hand, it's an easy way for the professional breeder to produce large amounts of plants in a short time. The result isn't 100% predictable. Besides, there has to be enough space to care for the plants until it is possible to decide which plant has the quality to be a parent plant.
- Seeding time: January until March
- Seeding temperature: One book mentions 15 to 20 degrees, another 20 to 25 (C).
- Germination time: 3 to 4 weeks, sometimes 2 to 3 months.
Why any division at all? If the container starts cracking under the pressure from the roots and a larger one gets to heavy to handle, division is the only answer. Dividing can be rather tricky: the roots clump up so densely that dividing them is only possible with an axe or a saw. Naturally, this is rather hard on the roots. Dipping the damaged roots into pulverized wood ash or sulphur will prevent them from rotting.
Plants which have grown in the garden are a bit easier to divide, as the roots have more space to spread.
Anyone interested in 'purebred' agapanthus has to revert to division.
Depending on its vigour, the parent plant can be divided after 4 to 5 years. The separated plant have to have two or three shoots, which must have well established roots.
The best time for division is immediately after the agapanthus has flowered, which is from August to September for the evergreens and plants kept in the garden year round. Deciduous agapanthus in containers can be divided in March just before their growing season.
Seedlings don't flower before their third or fourth summer. The plants usually don't flower in the year after their division, very small and young plants won't do so for two years.