The ‘Bishop of Oxford’ dahlia is a captivating choice for many gardens, drawing attention with its unique aesthetic. It is cherished for its distinct charm and visual appeal in mixed borders and perennial beds.
Distinctive Features
The ‘Bishop of Oxford’ dahlia features brilliant coppery-orange, open-centered blooms atop dark, almost black or bronze foliage. These single flowers measure up to 4 inches (10 cm) across, providing a luminous focal point. The rich, dark leaves offer a dramatic backdrop, making the vibrant flower color appear even more intense. This dahlia reaches a height of 2 to 3 feet (60 to 90 cm), producing a profusion of blooms from mid-summer until the first frost.
Cultivating Bishop of Oxford Dahlias
Site Selection and Planting
Choose a location that receives full sun for at least six to eight hours daily. The soil should be well-draining and rich in organic matter. Plant tubers about 4 to 6 inches deep and 18 to 24 inches apart in spring, after all danger of frost has passed. Dahlias do not tolerate waterlogged conditions, so ensure proper soil drainage.
Watering and Fertilizing
Maintain consistent moisture, especially during dry periods and active growth. Water deeply and regularly, keeping the soil moist but not soggy to prevent tuber rot. Once plants begin to bud and bloom, apply a balanced, low-nitrogen fertilizer every few weeks to encourage abundant flowering. Avoid high-nitrogen fertilizers, as they promote leafy growth over blooms.
Support and Deadheading
Provide support as ‘Bishop of Oxford’ dahlias grow to prevent stems from bending or breaking, especially in windy conditions. Staking young plants helps them grow upright and maintain structure. Regularly remove spent blooms, known as deadheading. This practice diverts energy from seed production, extending the blooming period.
Managing Pests and Diseases
Dahlias may attract pests like aphids, slugs, and earwigs. Inspect plants regularly for infestations and address them promptly with appropriate controls. Powdery mildew may appear in humid conditions; ensure good air circulation to prevent this fungal disease. Prompt removal of affected leaves limits its spread.
Winter Care
In regions with cold winters, ‘Bishop of Oxford’ dahlia tubers need to be lifted and stored indoors. After the first hard frost blackens the foliage, carefully dig up the tubers, remove excess soil, and dry for a few days in a cool, airy spot. Store the cleaned tubers in a cool, dark, and frost-free location, ideally between 45-50°F (7-10°C), nestled in peat moss or wood shavings to prevent drying.
Multiplying Your Plants
Propagating ‘Bishop of Oxford’ dahlias is most commonly achieved through tuber division, a reliable method for creating new plants. In spring, before planting, carefully separate the clumps of tubers, ensuring each division has at least one “eye” or growth point and a piece of the crown attached. This eye is where the new stem will emerge. Cuttings can also be taken from new shoots in spring, providing an alternative propagation method, though tuber division is generally more straightforward.
Addressing Growing Challenges
Common issues when growing ‘Bishop of Oxford’ dahlias include a lack of blooms or leggy growth. Insufficient sunlight can lead to sparse flowering; ensure plants receive full sun. Leggy growth (tall, stretched stems with few leaves) indicates inadequate light or over-fertilization with nitrogen. Adjusting sun exposure or using a low-nitrogen fertilizer promotes bushier plants and more flowers.