- Common name: lily of the Nile
- Type: perennial
- Zones: 6-11
- Site: full sun
- Soil: well-drained
- Flowers: blue or white
Agapanthus are tough survivors in a region of North America challenged by chronic drought. They are workhorses. The strappy evergreen or semi-evergreen leaves provide winter presence while blue or white flowers add a charge of color. There’s significant justification to look again to the raw genetic material held within this genus and reconsider the potential.
Agapanthus, its Latin name literally meaning “love” (agape) “flower” (anthos), is a genus of seven species. Its former position within the mammoth Lily family went through several iterations, first to the genus Amaryllis, then to onions (Allium), and then to a family of its own (Agapanthaceae). The common name, lily of the Nile, is based entirely on fantasy, as all species are native to dry outcroppings or moist mountain meadows of southern Africa. (Which is why they prefer full sun and draining soils with supplemental moisture during the establishment period.)
Over three decades ago, I was offered a division of a “tender” Agapanthus from an elderly but passionate gardener who had coddled it for years in a container. Ultimately this plant, labeled then as Agapanthus africanus, overfilled a large pot while presenting its spherules of light-blue flowers on erect stems to 3 feet, held above evergreen foliage, in mid to late summer. I was seriously hooked.
Later, upon moving to our mild-climate, seaside garden on the Kitsap Peninsula, I discovered beefy clumps of the same species thriving comfortably against the elements. Witnessing how well this plant fared in the full sun and sandy soil of our new garden was instrumental in the direction I ultimately took in developing the landscape, and was key in more fully exploring the genus. Now, with a collection of all the known species and over 80 named cultivars of Agapanthus, my knowledge of their cultural needs and the charms they bring to the late-season garden has matured substantially. Our front meadow, in a bluff-side expanse of sand, now transitions to a dreamy wash of blue, violet, and pure white from mid-July through early October.
That first Agapanthus I grew was labeled as A. africanus, but it was really A. praecox. It is this rather tender species that represents the mass institutional plantings throughout much of California. It is a good plant to illustrate the major differences between Agapanthus species.
A. praecox possesses a broad fleshy leaf that will remain evergreen if not exposed to extremely low temperatures. This attribute can be used as a predictive model as to the overall hardiness of any Agapanthus species or hybrid. Those tending towards being evergreen will not tolerate temperatures below 20 degrees Fahrenheit; the fully deciduous forms are surprisingly hardy, especially if mulched in late autumn (Zone 6). Any and all, however, make superb, low-maintenance, and extremely long-lasting container plants if provided a protected site during the winter months (more on keeping these in a container later).
Dan Hinkley calls Agapanthus Queen Mum™ the gold standard of the genus. Large white flowers bloom on stems up to 3 feet tall. Best planted in containers in Zone 7 and below. Photo by: Dan Hinkley.
A. Queen Mum™ was bred in Australia and to my mind is the gold standard of the genus—it is of exceptional form and the one to which all others should be measured. Enormous heads of large white flowers transition to deep blue at the base atop sturdy stems to 3 feet. Sadly, it has proven tender in the ground in the Pacific Northwest but will be valued as a container plant.
A. campanulatus represents more of the norm in the genus, a fully deciduous and decidedly hardier species. It is variable in color, running the spectrum from dark blue to medium blue to pure white. However, those that I have observed in the wild at high elevations of the Drakensberg Mountains of South Africa as well as on Table Mountain above Cape Town are of a medium blue, blossoming on stems to 2.5 feet. My wild collections of this species are the earliest to blossom in my garden, with medium-sized heads of sky blue by the end of May and attractive to both hummingbirds and swallowtail butterflies.
Agapanthus inapertus ‘Graskop’, the darkest cultivar to date, is very hardy and winter-deciduous. Provide full sun and draining soils. Sensational. Photo by: Alamy/Andrea Jones Images.
The pendulous tubular flowers of A. inapertus are the most distinctive of the genus and have relayed their genes to numerous hybrids that belie their parentage. The species, which is completely deciduous and hardier than most realize, send sturdy scapes skyward that may rise to an astounding 5 feet, capped by umbels of nodding tubular flowers in deep blue-violet tones. I am partial to a plant I first encountered in Cape Town that is now readily available in North America. A. inapertus ‘Graskop’ is the most seductive Agapanthus I’ve brought to flower, looking from a distance to be nearly as black as Iris chrysographes.
Attempting to divide any Agapanthus will put gardeners on notice that these plants are serious about survival, with impenetrable mats of fleshy, white, water-retentive roots. Regular division does not seem to be remotely imperative. And the impregnable tatami of roots will not allow an integration of other plants within a stand of them. Don’t consider, as I did, planting other bulbs in close quarters with Agapanthus. They will be overtaken by the expanding roots.
Why doesn’t my containerized Agapanthus blossom?
They don’t wish to be root-bound in a pot so repot frequently. Flower buds develop below ground during August and September—the best time to boost with a fertilizer to enhance blossoming (high P and K). A well-balanced N-P-K fertilizer should be applied as growth commences in spring. Protect plants from excessive wet. Don’t let them dry out and don’t keep them indoors.
Agapanthus ‘Loch Hope’ has A. inapertus in its blood and is one of the latest to blossom in the garden, at its finest in September. Though the flower heads of a deep blue ultimately form the orbs we identify with the genus, the buds first open in a distinctive pendulous fashion. Common genes are in other good selections currently available; Agapanthus ‘Jodie’, with nodding, late, and large flowers of sky blue is a particular favorite.
The darkest of the robust, semi-evergreen species is A. ‘Storm Cloud’. It’s a vigorous and nearly embarrassingly floriferous form, creating an eponymous roll of deep-blue thunder on sturdy stems to 3.5 feet. I’ve planted it in large drifts of 30-plus plants, in what I think to be a good combination with the blistering blast of red and orange Crocosmia. ‘Storm Cloud’, however, possesses more substance in name and flower than it does in general hardiness. It should be avoided in gardens suffering harsh winter temperature; 20 degrees Fahrenheit is enough to spoil the following year’s floral display if it doesn’t kill it outright.
There exist several named forms of Agapanthus with variegated foliage, with the majority offering what I consider a lackluster performance. Not so with the new A. ‘Gold Strike’ with frisky, broad yellow-margined foliage and a satisfying display of contrasting, mid-blue flowers. I use it to good effect, I think, in a container, unwilling to sacrifice a division to my climate to test general hardiness.
To say I have an Agapanthus breeding program is an overstatement. I have masses of Agapanthus and hordes of pollinators—two beehives, swarms of hummingbirds, and a flutter of butterflies. Generally speaking, they don’t excessively self-sow in the garden (the exception being the true species if more than one clone is present). And though I’m not purposefully breeding Agapanthus, pollinators oft have their way. A. ‘Blue Leap’ was a chance hybrid that’s now commercially available. It remains a favorite in my garden, with enormous heads of rich blue on sturdy stems to 3 feet and dependably hardy. Numerous others are on the horizon for eventual release.
I offer here an insufficient sampling of an enormous assemblage of the potential found within this sensational genus. Planted in mass, positioned singularly into the mixed border, or maintained in containers, there are few perennials that can equal the lasting effects of color and form from this genus of African plants.
This article was adapted from its original format for use on the web.
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