Agapanthus Donau

Agapanthus ‘Donau’ is a real summer showstopper, sending up sturdy stems topped with large, rounded heads of pale blue, starry trumpet flowers—each floret often marked with a deeper blue central stripe, giving the whole bloom a lovely “striped” look.

Flowering from mid to late summer, the flowerheads can be impressively sized (often 15–20cm across) and packed with around 40–60 florets, making it brilliant for borders, containers and cut-flower vases alike.

‘Donau’ forms a neat clump of strap-like green leaves and, like many agapanthus, performs best in full sun with free-draining soil—it particularly dislikes sitting cold and wet over winter. 

Planting Instructions

When to Plant:

Plant in spring once the risk of severe frost has passed, or in early autumn while the soil is still warm and workable.

Where to Plant:
Choose a sunny position for the best flowering. Plant into well-drained soil that stays lightly moist in summer. Agapanthus dislike being cold and wet in winter, so drainage is important. Ideal for mixed borders, patio containers, and gravel or coastal-style planting.

How to Plant:

• Depth: Plant so the crown is at soil level (the top of the root mass sitting level with the surrounding soil).
• Spacing: Space 30–45 cm apart to allow clumps to develop.
• Soil Prep: Work in a little well-rotted compost for moisture-holding, but avoid heavy, waterlogged ground—improve drainage with grit if needed.

Watering:
Water well after planting. Keep the soil evenly moist while establishing. Once established, agapanthus cope well but will flower best with occasional watering during dry spells.

Aftercare Tips:

• Feed in spring and early summer with a high-potash feed to encourage flowering.
• Deadhead spent blooms for a tidier look, or leave seedheads for structure.
• In colder areas, add a winter mulch to protect the crown, especially in the first year.

Top Tip:
Agapanthus ‘Donau’ is fantastic in pots—and slightly “snug” roots can help encourage flowering. Place containers in the sunniest spot you have, and protect from winter wet.

Plant Details

Flowering Period:
Mid to late summer (typically July–August)

Height:
Approx. 70cm (with varieties often maturing around 0.5–1m depending on conditions)

Position:
Full sun

Soil:

Moist but well-drained (avoid winter waterlogging)