African lily

Identification and origin

Agapanthus praecox belongs to the amaryllis family, Amaryllidaceae. It is native to South Africa, from the southern Cape Provinces to KwaZulu-Natal, in a region where rain falls throughout the year. It is the most widely grown agapanthus species, and most garden agapanthus descend from it. The name comes from the Greek agape, love, and anthos, flower; praecox means “early.” Dutch settlers brought it to European conservatories as early as the 17th century, and name confusion is still common: it is also sold as A. africanus, A. umbellatus, or A. orientalis.

It is an evergreen perennial that forms dense clumps from short rhizomes and a tangle of fleshy roots. The glossy green, strap-shaped leaves are 12 in – 2 ft long and 0–1 in wide. The clump reaches about 2.5 ft tall and 2 ft wide.

In summer, hollow stems 2–5 ft tall carry rounded clusters 4–6 in across that can hold about a hundred flowers. Each funnel-shaped flower has six tepals, light to dark blue, violet, or white, with a darker stripe down the center. The bloom lasts four to six weeks and attracts bees and butterflies, and the flowers are good for cutting. They leave three-sided capsules full of seeds.

Cultivars include ‘Albiflorus’ (white), ‘Blue Bayou’ (deep blue), ‘Queen Mum’ (white with a purple flush at the base), and ‘Stevie’s Wonder’ (violet-blue). The species is so vigorous that it is considered a weed in parts of Australia.

Light

Full sun is essential, with at least six hours of direct sun a day. In shade the plant grows but blooms little or not at all. The flower stems lean toward the light, so a south- or west-facing spot gives the straightest clumps. During winter storage, keep it somewhere very bright, because an evergreen agapanthus keeps living through its leaves.

Watering

Water needs follow the plant’s cycle. In spring, when growth resumes, never let the root ball dry out: a shortage of water at that stage prevents flower buds from forming. From spring to early fall, water whenever the surface of the mix is dry, soaking the whole root ball, then empty the saucer. A potted plant that dries out completely in summer can fail to bloom the following year.

In the ground, an established clump needs little water; in a very dry summer, a deep soaking late in the season helps next year’s bloom. In winter, keep the mix on the dry side and water lightly, just enough to keep the roots from drying out completely.

Potting mix

It likes fertile soil that is moist but well drained, loamy or sandy, with an acidic to alkaline pH. Standing water in winter is fatal: in heavy, wet soil, grow it in a container instead.

In a container, use a pot at least 8–9 in across and a peat-free potting mix, or combine one-third good garden loam with two-thirds organic potting soil. Agapanthus is a heavy feeder: during active growth, apply a high-potassium fertilizer such as tomato food about every two weeks. Stop in fall and winter.

Temperature

Being evergreen, A. praecox is more tender than the deciduous agapanthus. It tolerates low temperatures but does not survive being frozen: its limit is around 34–41 °F. In the ground it is grown in USDA zones 8b to 11b, with a thick winter mulch in borderline areas.

In a container, move it in fall into a cool greenhouse, a sunroom, or a very bright room at about 55–61 °F, or set it at the foot of a sheltered wall with the pot wrapped in several layers of frost cloth. A winter that is too warm triggers early, poor-quality flowers.

Repotting

Contrary to a common belief, it does not bloom better when tightly pot-bound, and a pot that is too large also hurts flowering. Repot every two or three years into a container 1–2 in wider, at the same depth as before. When planting rhizomes, cover them with about 2 in of soil. When repotting is no longer practical, divide the clump.

Pruning

No pruning is needed. Cut spent flower stems at the base to encourage more blooms, or leave a few decorative seed heads into early winter. Remove damaged or yellowed leaves as they appear.

Propagation

Division is the most reliable method: it reproduces the cultivar exactly and rejuvenates old clumps, roughly every four or five years. For a potted plant, divide right after flowering, in late summer; in the ground in cold regions, wait until spring. It is hard work, since the fleshy roots are heavy and tangled: separate pieces with several shoots, trim the roots if needed, replant, and water regularly until they establish. Dividing too often reduces flowering.

Seed is sown at 55–59 °F, as soon as it ripens or in spring. Seedlings vary and take several years to bloom.

Common problems

• No flowers: plant too young, shade, drought in spring or summer, too little fertilizer, poor winter protection, an oversized pot, or recent division.
• Misshapen buds with brown patches that dry up or rot without opening: agapanthus gall midge, a tiny fly whose yellowish larvae live inside the buds. Destroy affected flower heads and, for container plants, replace the mix, where the larvae pupate.
• Holes in leaves: slugs and snails.
• Pests: aphids, scale insects, spider mites.
• Diseases: gray mold, root rot in waterlogged soil, powdery mildew, Verticillium wilt, viruses.
• Damaged foliage at the end of winter: frost or overly cold winter storage.

The same symptom can have several causes: check light, watering, temperatures, and the condition of the roots before drawing conclusions.

Toxicity

All parts of the plant are harmful if eaten. For people, toxicity is low: the sap irritates the skin and eyes, and swallowing it can cause irritation or even ulcers in the mouth. Wear gloves when dividing clumps. In dogs and cats, the saponins it contains can irritate the digestive tract; toxicity is probably low unless an animal eats a large amount. If a pet tends to chew on plants, keep it out of reach and, if any is swallowed, contact a veterinarian or a poison control center.