Despite its common name, lily of the Nile is not a lily nor did it originate in the vicinity of the Nile River. Its origins in South Africa give greater credence to the common name "African lily." The plants are grown and admired in warm to temperate areas in all parts of the world.
In summer, clusters (umbels) of funnel-shaped blue, purple, or white flowers arise above the foliage on tall, erect stalks (scapes). Each cluster may have up to 100 florets, and the stalks may reach up to 6 feet or more tall in some species. Evergreen or deciduous linear, basal leaves subtend the flowers. Roots are fleshy rhizomes.
Classification of Agapanthus is confusing, and even experts have difficulty. Over the years, Agapanthus has changed families several times, being at one time or another assigned to Liliaceae (lily), and Alliaceae (onion), or being assigned its own monotypic family, Agapanthaceae. APG III taxonomic system assigns it to the family Amaryllidaceae and recognizes these species: A. africanus, A. campanulatus (with one subspecies), A. caulescens, A. inapertus (with five subspecies), and A. praecox (with three subspecies).
According to many experts, most selections found in markets today are cultivars or hybrids of Agapanthus praecox. The species is variable, and three different subspecies are recognized: A. praecox subsp. minimus, subsp. orientalis, and subsp. praecox. According to Alice Notten of the Kirstenbosch National Botanical Garden in South Africa and other experts, plants labeled Agapanthus africanus are usually hybrids or forms of A. praecox. According to these experts, Agapanthus africanus is very difficult to grow and has very specific growth requirements that cannot be met by most gardeners.
According to Scott Ogden in Garden Bulbs for the South, not all agapanthuses do well in Southern gardens. According to Ogden, A. africanus is the species that does best in the South. He surmises that it is sometimes difficult to distinguish the species, for they are often named incorrectly. One way to tell is to count the flowers. A. africanus has less than 30 florets per umbel. Agapanthus orientalis has between 40 and 100 florets per umbel.
The APG III taxonomic system does not recognize A. orientalis, but it does list A. praecox subsp. orientalis. Since it is generally recognized by most experts that almost all the evergreen agapanthus in cultivation are cultivars or hybrids of A. praecox, I would guess that Ogden's A. africanus is also a subspecies of A. praecox. I like the way Steve Christman of Floridata.com puts it. He says, "Agapanthus praecox, A. africanus and various hybrids are most often grown in American gardens." By putting it this way, he accepts either as excellent plants for Southern gardens. Judging from my research, most plants labeled as Agapanthus africanus are actually A. praecox.
However, many selections can be found labeled Agapanthus africanus. Such favorites as ‘Peter Pan', ‘Ellamae', ‘Elaine', and the many others are often listed as cultivars of this species. Both A. praecox and A. africanus are evergreen with foliage that is attractive even when plants are not in bloom. Often the evergreen types are used as a groundcover in areas where the foliage is hardy. Variegated types are also available that offer a bright spot of color in the landscape.
Other species of Agapanthus are deciduous. Because leaves of the deciduous species die down in the winter and the roots are protected somewhat from the cold, they tend to be hardier than the evergreen species. Their hardiness range can be extended somewhat by burying the rhizomes deeper and covering with a layer of mulch during the winter.
The deciduous Agapanthus campanulatus (bell agapanthus) grows in colonies and its flowers are light to dark blue with darker blue stripes. From this species comes the Headbourne hybrids that are hardy to Zone 6. Other deciduous species include A. caulescens (virtually unknown as a garden plant but sometimes found in botanic gardens) and A. inapertus.
Agapanthus inapertus, sometimes called "drooping agapanthus," is noted for its pendulous, very tubular flowers that bloom in late summer or early fall. Flowers are usually deep blue (occasionally white), and some cultivars are almost navy blue, such as Agapanthus inapertus subsp. pendulus ‘Graskop'. Strappy leaves are narrow and gray-green.
Agapanthus requires well-drained, fertile soil and bloom best in full sun to light shade. When planting a new bed, amend the soil with generous amounts of organic matter if needed, and place the fleshy roots about two inches deep and four to six inches apart. Water well to settle the soil around the rhizomes and keep the bed moist during the spring and summer. The foliage will emerge in a few weeks.
Flowers bloom during the summer and last for several weeks. When blooming has finished, cut the flower stalks back to the ground unless you intend to save seeds for propagation. Allow the energy that might be used for making seeds to replenish the rhizomes for next year's flowers.
Divide African lilies when they become root bound. The evergreen species need to be lifted and divided at least every four years or so to ensure flowering, but the deciduous species are best left undisturbed for about six years. The best time to divide both types is in spring before new growth begins. Dig and cut the rhizomes so that each section has a few roots. New plants can also be started from seed which should be sowed when seeds are fresh in well drained seedling mix, placed in semi-shade, and kept damp. Seed-started plants can be expected to bloom in about three years from planting.
Agapanthus seems to do best when a little overcrowded and are therefore well suited to container cultivation. In cooler climates African lilies are grown in containers that can be moved indoors in winter. They are popular as potted plants at poolside, on decks and porches, and are even adaptable to seaside locations because of their salt tolerance. The flowers of African lily last quite long and are great as cut flowers. Even dried flower heads are attractive and can be used in dried arrangements.
The thing is to not let the confusing nomenclature keep you from growing these beautiful plants. Find some that are adapted to your area and enjoy them regardless of the name they are given by the grower. A rose is a rose is a rose. Right?
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