Dahlia Imperialis

Dahlia Imperialis: Towering Tuber with Sky-High Blooms

Create a dramatic and breathtaking focal point in your garden with the Dahlia Imperialis tuber. This remarkable plant, known for its immense size, grows to a towering height of 2–4 m with a spread of 1–1.5 m. It features thick, bamboo-like hollow stems and huge pinnate leaves, giving it a striking tropical appearance. High on each cane, a profusion of nodding, lightly ruffled blooms emerges. The single to semi-double flowers, measuring 10–13 cm, have pale lavender-pink petals surrounding a vibrant golden-orange disc, creating a mesmerizing “sun-through-mist” effect when viewed from below. With 30–35 blooms opening on each cane, this dahlia is a true spectacle.

Dahlia Imperialis is the perfect choice for a statement specimen or for adding a touch of the tropics to your landscape. Its sky-high stems can be harvested for impressive cut flower arrangements, making it a popular choice for hotel lobbies and event décor. With proper support and care, this dahlia will provide a spectacular display of fireworks-tall blooms throughout the winter months.

Growing Calendar

• Plant tubers: late February – early March (when soil temperature is ≥ 18°C).
• First buds: mid-October.
• Peak display: November – December.
• Cut back / rest: mid-January.

Best Uses

• Statement specimen against a warm, sheltered wall.
• Tropical-look borders with cannas, bananas, or palms.
• Sky-high cut stems for hotel lobbies or event décor.

Planting & Care Guide

• Soil: Dig 50 cm deep; blend in 10 L of well-rotted compost and 1 cup of blood/fish/bone per plant.
• Depth & spacing: Lay tuber horizontally 6 cm deep, 1 m apart; backfill without air pockets; water 1 L at planting.
• Water: Keep evenly moist for the first 6 weeks, then deep-soak weekly; increase to twice weekly in midsummer heat.
• Feed (Fertilizing): Side-dress with an organic 5-5-5 fertiliser every 6 weeks until September.
• Support: Drive a 3 m stake or secure stems to a pergola or wall as they grow.
• Maintenance: Pinch side shoots at 1 m if you need fewer, sturdier canes; otherwise, let it tower naturally.