Agapanthus Giant Blue

Plant size after 3 years
Height: 1.2 meters (4 feet), Spread: 0.6 meters (2 feet)

Foliage and Flower Colour
Foliage: Dark green, strap-like leaves
Flowers: Deep blue, trumpet-shaped blooms
Flowering Months: July to September

USDA Plant Hardiness Zones
Suitable for Zones 7 to 10

GardenAdvice Notes
Agapanthus Giant Blue, also known as African lily, is native to South Africa and belongs to the Amaryllidaceae family. It’s renowned for its dramatic, showy blooms that make a great choice for cut flowers. This plant is valued for its drought tolerance and its ability to thrive in coastal areas, as it can withstand salt spray. Historically, parts of the plant were used in traditional African medicine. While deer-resistant, the flowers are highly attractive to pollinators like bees and butterflies.

Ideal Soil Type
This Agapanthus thrives in well-draining, loamy or sandy soil with a neutral to slightly acidic pH (6.0 to 7.5). It benefits from soil enriched with organic matter like compost, which helps retain moisture while ensuring adequate drainage. Avoid overly wet soils to prevent root rot.

Location and Aspect
Best grown in full sun to partial shade. For optimal flower production, plant in a location that receives at least six hours of sunlight per day. In hot climates, partial shade during the hottest part of the day can protect the plant from scorching. Agapanthus is perfect for borders, raised beds, and containers, where it can be protected from strong winds that might topple its tall flower stems.

Pest and Disease Problems
Agapanthus Giant Blue is generally resistant to pests and diseases, though it may occasionally attract slugs and snails, which can be managed with barriers, traps, or organic slug pellets. Fungal infections can occur if the soil is too wet or poorly drained. To avoid this, plant in well-draining soil and ensure good air circulation around the plant.

How to Propagate
Propagation is typically done by division or seed:

• Division: The best time to divide Agapanthus is in early spring or autumn. Carefully dig up the clump, separate the offsets, and replant in fresh soil.
• Seed: Agapanthus can also be propagated from seed, though this method takes longer to establish flowering plants. Sow seeds in autumn or spring, using a well-draining seed-starting mix. Keep the soil moist and warm for germination, and transplant when large enough.

Pruning, Cutting Back, and Dividing
Deadhead spent blooms to encourage more flowering. In autumn, cut back any faded foliage and remove flower stems. Divide plants every 3-4 years in spring or autumn to maintain vigour and prevent overcrowding.