African lilies (Agapanthus) are captivating perennial plants native to South Africa. Also known as Lily of the Nile, they are not true lilies nor from the Nile River region. These plants produce showy, rounded clusters of blue, purple, or white trumpet-shaped flowers atop tall stalks, emerging from clumps of long, strap-shaped leaves. Valued for their striking appearance and ease of cultivation, African lilies are a favored choice for many gardeners. Depending on the variety, their foliage can be evergreen, retaining leaves year-round, or deciduous, dying back in colder months.
Planting Your African Lily
African lilies flourish in full sun, ideally six to eight hours daily, though partial shade benefits them in hotter climates. Well-draining soil is crucial, as they do not tolerate waterlogged conditions. Amend heavy clay soil with grit or sand to enhance drainage.
Plant African lily rhizomes in spring after the danger of frost has passed and soil temperatures reach 50°F (10°C). Dig a hole deep enough to cover rhizomes by about two inches, ensuring pointed ends face upward. For established plants, maintain the original container’s planting depth. Space multiple African lilies 12 to 18 inches apart. For container planting, select a pot at least 12 inches wide with drainage holes, using a fertile, well-draining potting mix.
Routine African Lily Care
Consistent watering is important, especially during active growth. While established African lilies tolerate some drought, they perform best with regular moisture. Water thoroughly every one to two weeks, allowing the soil to dry slightly between applications to prevent overwatering and root issues.
African lilies benefit from a balanced fertilizer application. Fertilize twice during the growing season: once in early spring and again two months later. A balanced formula like 10-10-10 or 5-5-5, or one slightly higher in phosphorus, is suitable. Cease fertilization by late summer to prepare the plant for dormancy.
Pruning and deadheading spent flowers encourages new blooms and prevents seed production. Remove entire flower stalks at their base once blooms fade. Trim yellowing or damaged foliage from evergreen varieties at any time. For deciduous types, allow leaves to die back naturally to reabsorb nutrients into their rhizomes before removal.
Winter Care and Overwintering
Winter care for African lilies depends on the variety and climate zone. Deciduous varieties, which lose their leaves, are generally more cold-hardy, tolerating temperatures down to -10°F (-23°C) in USDA zones 6 and 7. In these cooler regions, in-ground deciduous plants benefit from a protective mulch layer over their crowns before the first hard frost.
Evergreen African lily varieties are less cold-tolerant, suited for USDA zones 8 through 11. In areas where temperatures consistently drop below freezing, protecting evergreen types is crucial. In-ground plants in marginal zones may benefit from heavy mulching, but remain vulnerable to severe cold.
Potted African lilies offer flexibility for winter protection. Before the first hard frost, bring containerized plants indoors to a cool, bright, frost-free location, such as a garage with a window or an unheated greenhouse. During winter dormancy, reduce watering significantly, providing moisture lightly (perhaps once a month) to prevent the soil from becoming bone dry. Optimal indoor temperatures for overwintering range from 40°F to 50°F (4°C to 10°C) to prevent early dormancy break.
Troubleshooting Common Issues
African lilies are generally robust, but can encounter issues. Pests like mealybugs, slugs, and snails may affect them. Mealybugs, appearing as white, waxy insects, are managed with horticultural oil. Slugs and snails, which feed on foliage, can be hand-picked or deterred with shallow pans of beer. Thrips cause distorted growth and silvery leaves; cultural controls like removing affected parts or water sprays can help.
Root rot is a common disease, primarily caused by overwatering or poorly draining soil. Symptoms include yellowing leaves and a general decline in vigor. Proper drainage and avoiding excessive moisture are the best preventive measures.
Yellowing leaves can stem from various causes beyond root rot. Natural seasonal senescence, especially for deciduous varieties, causes leaves to yellow and die back in autumn and winter. Overwatering can lead to yellowing due to lack of oxygen to roots. Nutrient deficiencies, such as nitrogen or iron, can also manifest as yellow foliage. Cold damage in evergreen varieties can result in yellow, limp leaves.
Propagating African Lilies
African lilies are readily propagated through division, which also rejuvenates overgrown clumps. The best time for division is early spring, just before new growth, or early fall after flowering. To divide, carefully lift the entire plant clump. Use a sharp spade or two garden forks back-to-back to separate the root ball into smaller sections. Each new division should have at least two growing points for successful establishment.
Toxicity and Safety
African lilies contain compounds toxic to humans and pets if ingested. Contact with the sap can also cause skin irritation.