Lily of the Nile / African Lily
Agapanthus praecox
description
Lily of the Nile is a clump-forming perennial with rounded heads of blue or white summer flowers.
benefits
- Flowering
- Suitable for containers
warnings
- Toxic to cats
- Toxic to dogs
How to care for Lily of the Nile
sunlight
In its South African habitat, Lily of the Nile grows in open, sunny places. Give it the brightest spot you have to encourage sturdy leaves and the best summer flowering.
Full sun
A south- or west-facing position is ideal. Aim for at least 6 hours of direct sun outdoors or in a very bright window. More sun usually means more flower stems, provided the plant is watered during hot, dry weather.
Tolerated light shade
It can manage a few hours of shade, especially where afternoons are intensely hot, but dense shade leads to leafy growth and fewer flowers.
watering
Water deeply, then wait until the top 2-5 cm of compost feels dry before watering again. Agapanthus likes steady moisture while growing, but its fleshy roots need air around them.
Spring - summer
In a pot, water about once or twice a week in warm, bright weather. Soak the root ball until water drains out, then empty the saucer. Check below the surface rather than following a fixed schedule.
Autumn - winter
As growth slows, water roughly every 2-3 weeks, only when the compost has dried further down the pot. Keep evergreen plants lightly moist, while deciduous types can stay almost dry once their leaves have died back.
Plants in strong sun, heat, small pots, or fast-draining compost dry faster. Cool rooms, low light, large pots, and dense compost keep moisture longer.
humidity
Typical home humidity
Agapanthus comes from open, breezy parts of South Africa, so it does not need tropical humidity. Average household air is suitable, with around 45-60% preferred during active growth.
It usually tolerates humidity down to about 35%, but prolonged dry heated air can leave leaf tips and edges brown or crisp. Check the compost too, as underwatering causes similar symptoms.
- Move it away from radiators and hot air vents.
- Use a humidifier nearby if humidity remains below about 35%.
- Keep good airflow around the leaves rather than misting them regularly.
temperature
Active growth
Winter minimum
Native to South Africa, Lily of the Nile enjoys warm summers but is less reliable in cold, wet conditions. Keep container plants cool and bright in winter, ideally around 5-10°C (41-50°F). Evergreen cultivars need more frost protection than deciduous types.
nutrition
March - August
Feed while leaves and flower stems are actively growing. For pots, use a balanced liquid fertilizer at about half strength every 2-4 weeks; plants in fertile garden soil usually need only a light spring application. Stop feeding once growth slows after flowering.
Phosphorus
Phosphorus supports strong roots and flowering. A balanced fertilizer provides enough without pushing leafy growth at the expense of blooms.
Potassium
Potassium helps support sturdy flower stems and overall resilience. It is useful during bud and bloom development, especially for container-grown plants.
soil
Rich, moisture-retentive but free-draining soil
Agapanthus grows from fleshy roots that appreciate steady moisture in summer but can rot in soggy soil. Use a fertile loam-based mix with compost and grit, perlite, or coarse sand to keep air around the roots.
pH 6,0 - 7,0
This is slightly acidic to neutral, which suits most garden soil and quality potting mixes. Avoid strongly acidic mixes and use a little garden lime only if your soil is known to be very acidic.