But it's among the first plants I replace, should I lose it. I have several agapanthus planted in February that have not bloomed. For best results, these tuberous-rooted perennials should receive winter sun and partial summer sun. It's important to water well while the plants grow in spring. Agapanthus are fertilized in early spring and after the plants have bloomed.
Bone meal works well.
Plant age, weather and fertilizer are among the possible reasons your plants did not bloom. I'm not sure how old your agapanthus are, but seedlings or young plants can take three or so years to bloom. Sometimes plants just need time to establish before flowering. Agapanthus are generally planted October-February. You planted yours at the end of this time frame, and then we had a long, cool spring with few sunny days to encourage flowering.