We're offering you a Dahlia 'Black Forest Ruby' Plants for £5.99, saving you up to 40% off Thompson and Morgan's's price of £9.99 (correct as of 16.04.2026).

Bold Colour Contrast

Dahlia 'Black Forest Ruby' is a captivating perennial from the Asteraceae family, prized for its rich scarlet to deep red blooms that stand out dramatically against jet-black foliage. This variety is bred for both beauty and performance—its semi-double to double flowers create a luxurious, layered look that brings instant impact to any garden.

Why Choose 'Black Forest Ruby'?

• Bold Colour Contrast: The fiery red petals pop against dark leaves, creating a show-stopping display from midsummer right through autumn.
• Late Season Performer: When many summer flowers begin to fade, this dahlia keeps your garden vibrant well into the cooler months.
• Bushy & Compact: With a mature height of 70cm and spread of 30cm, it fits perfectly in borders, beds, and patio containers—ideal for smaller spaces or as a dramatic focal point.
• Excellent Cut Flower: The sturdy stems and prolific blooms make it perfect for bold indoor arrangements.

Growing Guide

• Planting Time: Plant jumbo plug plants outdoors after the last frost—typically late spring in the UK.
• Location: Prefers a sunny spot with well-drained soil. Dahlias thrive best in fertile, humus-rich ground.
• Caring For Your Dahlia: Water regularly during dry spells and feed with a balanced fertiliser every few weeks through the growing season. Deadhead faded blooms to encourage further flowering.
• Overwintering: In colder regions (RHS hardiness rating H3), lift tubers after the first frost and store them in a cool, dry place until spring.
• Mature Size: Height: 70cm (28in); Spread: 30cm (12in).

Design Ideas & Companions

• Add impact to beds and borders by pairing with ornamental grasses or silver-leaved perennials like Artemisia.
• Create vibrant patio displays by mixing with other late-flowering dahlias or contrasting white cosmos.
• Dramatic enough to stand alone as a feature plant in a container or border edge.

FAQs

• When is the best time to plant Dahlia 'Black Forest Ruby'?
  The ideal time is after the last frost in late spring when soil has warmed up.
• How tall does this dahlia grow?
  'Black Forest Ruby' reaches about 70cm (28in) in height with a spread of 30cm (12in).
• Does it need lifting over winter?
  If you live in areas prone to hard frost, lift tubers after the first frost and store them indoors until spring planting.