Dahlia 'Bishop of Llandaff'

The Dahlia 'Bishop of Llandaff', a stunning member of the Asteraceae family, is a highly prized tuberous perennial native to the mountainous regions of Mexico. First introduced in the 1920s, it remains one of the most famous and beloved Dahlia cultivars in the world. It is renowned not just for its brilliant floral display, but also for its dramatic, deeply cut, dark bronze-to-almost-black foliage, which creates a striking contrast in any garden setting.

This cultivar features semi-double, brilliant cardinal-red flowers measuring about 2 to 3 inches across. The dark, fern-like foliage provides a perfect backdrop for the vivid blooms. As a member of the Asteraceae family, what appears to be a single flower is actually a composite flower head containing central disc florets surrounded by radiant red ray florets. The plant exhibits an upright growth habit, typically reaching a height of 3 to 4 feet.

The floral formula is ⊕ ⚥ (Disc) / % ♀ (Ray) K(pappus) C(5) A(5) G(2). Typical of the Asteraceae family, it has an inflorescence known as a capitulum, featuring actinomorphic bisexual disc florets in the center and zygomorphic female ray florets on the perimeter. This structure makes the flower highly accessible and attractive to bees and butterflies.

Dahlias demand full, direct sun (at least 6-8 hours) and rich, well-draining soil. They are heavy feeders and require regular watering and fertilizing during the growing season. While perennial in warm climates (USDA zones 8-11), the tubers are extremely frost-sensitive. In colder regions, the tubers must be dug up after the first frost, dried, and stored indoors over winter to prevent rot.

The Dahlia is the national flower of Mexico, symbolizing elegance and dignity. The 'Bishop of Llandaff' specifically was honored with the Royal Horticultural Society's Award of Garden Merit for its outstanding reliability, historical significance, and enduring beauty in landscape design.

It is mildly TOXIC to dogs and cats. Ingestion of the tubers or foliage can cause gastrointestinal upset and mild dermatitis, so it should be planted carefully in pet-friendly yards.

Often confused with other dark-leaved Dahlias (like 'Bishop of Auckland') or certain varieties of Zinnias. Zinnias, however, are grown from seed annually, lack the tuberous root system, and do not possess the specific deep bronze foliage characteristic of this Dahlia. Pair with the vibrant Aster or the resilient Pelargonium for a brilliant late-summer display. Discover more in our Flower Identifier hub.