Since there can never be enough blue-flowered plants in a garden, getting Agapanthus to succeed has been a goal of mine going back a long time. I made two attempts in our mid-Ohio garden (zone 6a). The first was with a seed strain, the Headbourne hybrids often touted as reliably hardy in Great Britain. The problem of course is that there’s a vast gulf between “hardy” over there and surviving much colder and more extreme winter weather on the other side of the Atlantic. My first-year seedlings grew adequately if not spectacularly and promptly vanished over their initial winter. Next up was a potted Agapanthus I found for sale during a trip to New Hampshire. It actually survived two winters in a less-than-ideal location before succumbing, without ever flowering.
I’d put the idea of growing these plants on hold, but then found a sizable plant identified only as “Hardy Blue” for sale at a local nursery.
Not long after scoring this plant, I found Agapanthus hybrids “Galaxy Blue” and “Galaxy Light Blue” at a local nursery, with tags claiming zone 6 hardiness. The Galaxy hybrids also include a dwarf 2-footer (“Little Galaxy”) and a white version, though I’m not sure what the attraction is in having a white Agapanthus. Might as well grow garlic chives instead and have something good to eat in addition to similar white flowers.
I installed a total of five reputedly hardy Agapanthus in our central Kentucky garden in 2021, and all of them flowered for several glorious weeks in June-July.
As of fall, vegetative growth was less vigorous than I’d hoped, so I decided not to risk them in-ground and dug up all but one plant for potted cool winter storage. I left a single plant of “Galaxy Light Blue” out to fend for itself, well-mulched. Come spring of ‘22 and “Galaxy Light Blue” re-emerged and went on to flower, as did all of the re-installed potted Agapanthus except (for some reason) “Hardy Blue”. In fall of ‘22 I resolved to bite the bullet and see if all plants would overwinter in the ground, mulching heavily and hoping for the best. We’ll see how a season low (so far) of -9F has challenged them.
Helping me go through with a bold approach to overwintering these plants is the ability to raise progeny from seed, which should be sizable enough in ‘23 to flower for the first time. Seed-grown plants (which may well differ from their parents) are currently in dormant cool storage at 38-50F.
Speaking of growing from seed, I’m experimenting with "Storm Cloud", a vibrant deep blue-purple Agapanthus. It’s rated hardy only through zone 7 so my outdoor planting might be iffy but is again backed by having a couple of pots in storage.
I’ve found that Agapanthus is not difficult to grow in decent, well-drained soil in full sun, with mulching in summer to keep their roots relatively cool and moist. In my opinion they’re best used as foreground, “see-through” plants, playing well with many different garden companions. This might be the year I pair them with variegated tapioca.
The Agapanthus collection has grown to eleven plants. Hoping for lots of blues this year.