I was feeling a bit homesick for the California Agapanthus of my youth when I found Agapanthus 'Blue Yonder'. It was in a catalog that I didn't trust very much, but it said it was hardy to zone 6. Unheard of! Zone 7 has always been very borderline for the Agapanthus crowd. But I had to try it. I've had it for a few years now, and it has grown, and now blooming more than it has before. I've learned a few things in the past few years.
Agapanthus prefers a Mediterranean climate. No question about that. Even this hardy form has struggled. The leaves are late to emerge, and when they do, the tips are always brown. The growth has been very slow. Although my plants have expanded, there were very few flowers the first two years, and the plants are very very small compared to the non-hardy forms in California, only about 10 inches tall (the flower stalks taller). The flowers and umbels are also quite small, an umbel being about 3 inches across, which is miniscule by California standards. Also, they need a lot of water to be happy. The one that died was because the drip emitter to that plant wasn't quite reaching it. Two that I transplanted from under a tree that had grown since planting them, were not happy this year, with only one umbel between the two of them.
It is clear that although these are Agapanthus, they are not the same as the Agapanthus in California. Maybe if I planted these there, they would be different. This does not mean that they are not worthwhile garden plants here, however. Although they might need some coddling (which I have yet to give them), the vibrancy of the color is incredible, and stands out from across the yard. This photo is after several weeks of bloom, so the bloom season is long. They have survived and grown despite no extra winter protection, which was surprising. Overall, I'm enjoying them quite a bit, but I think I'll have to pamper them a bit more. More water, more fertilizer.