Agapanthus are easy to grow from seed and you may get flowering plants in as little as two years.
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.
They are easy to grow, preferably sown fresh and pricked out individually next spring. With a bit of luck they should come to flower the following season.