The ‘Bishop of Dover’ dahlia is a captivating choice for gardeners, celebrated for its elegant and striking presence. This dahlia variety brings a unique aesthetic to garden designs, drawing attention with its distinctive features. Its popularity stems from its visual appeal and ability to complement diverse planting schemes.
Unique Attributes of ‘Bishop of Dover’ Dahlia
The ‘Bishop of Dover’ dahlia features single flowers, typically pristine white or cream, often with subtle hints of lilac or blush pink. A cheerful yellow, pollen-packed center provides striking contrast and attracts pollinators like bees and butterflies.
Beyond its blossoms, the foliage is notable for its dark, almost black, or deep bronze-maroon coloration. This rich leaf color enhances the visual impact of the lighter flowers, creating a dramatic and elegant display. The plant typically reaches 2 to 3 feet (60-90 cm) tall and spreads 1.5 to 2.5 feet (50-75 cm). Blooming from mid-summer until the first frost, ‘Bishop of Dover’ provides continuous color and a sophisticated touch to garden borders, beds, or containers.
Growing and Caring for ‘Bishop of Dover’ Dahlia
To grow ‘Bishop of Dover’ dahlia, select a site with full sunlight (at least six to eight hours daily). A sheltered spot protects plants from strong winds, preventing stem and flower damage.
Dahlias prefer rich, well-draining soil with a neutral to slightly acidic pH (around 6.5). Amend heavy clay soils with organic matter like compost or well-rotted manure to improve drainage and provide essential nutrients. For containers, use a quality, well-draining potting mix.
Plant dahlia tubers outdoors in spring after all danger of frost has passed and the soil temperature has warmed to at least 60°F (15°C). Plant tubers 4 to 6 inches deep with the ‘eye’ facing upward. Space individual tubers 12 to 18 inches apart for adequate air circulation and growth.
Watering needs careful management. Avoid watering tubers immediately after planting until green shoots emerge, as excess moisture can lead to rot. Once sprouts appear, water deeply once or twice a week, allowing the soil to dry slightly between waterings. Consistent moisture is important, especially during dry spells and blooming.
Fertilize dahlias with a low-nitrogen, higher phosphorus and potassium formula (e.g., 5-10-10 or 10-20-20). Apply fertilizer every few weeks from mid-summer until early fall to encourage continuous blooms.
Regular deadheading promotes more blooms and maintains plant vigor. Remove spent flowers by cutting the entire stem, preventing the plant from expending energy on seed production. As ‘Bishop of Dover’ dahlias can reach a significant height, provide support through staking or caging to prevent stems from flopping, especially when laden with flowers.
Preparing ‘Bishop of Dover’ Dahlia for Winter
In regions with freezing ground, ‘Bishop of Dover’ dahlia tubers need to be dug up and stored indoors for winter protection. Dig after the first hard frost blackens the foliage, signaling dormancy and allowing tubers to mature and store energy for the next season.
Cut back foliage, leaving a 4 to 6-inch stem. Carefully lift tubers from the soil, avoiding damage, as punctures can lead to rot during storage. A garden fork can gently loosen the soil around the clump before lifting.
Once lifted, gently shake or brush off excess soil. Rinse tubers with water to remove dirt, then allow them to dry and cure in a cool, dry, well-ventilated location for a few days to a week. Curing helps toughen the skin and prevent rot.
For storage, pack dried tubers in materials like peat moss, vermiculite, or wood shavings. These materials regulate humidity and prevent shriveling or rotting. Store them in a cool, dark, frost-free area where temperatures remain consistently between 40-50°F (5-10°C) and humidity is around 80-90%. Periodically check stored tubers and remove any showing signs of rot or disease. In very warm climates (USDA zones 8-11) where the ground does not freeze, tubers can remain in the ground with a thick layer of mulch for insulation.
Troubleshooting Common Dahlia Issues
Dahlias can encounter common gardening challenges. Pests such as aphids, slugs, earwigs, thrips, and spider mites are frequent visitors. Aphids and thrips, small sap-sucking insects, cause distorted leaves and flowers and may transmit viruses. Slugs and snails damage young, tender foliage. Inspect plants regularly for signs of infestation; insecticidal soaps or horticultural oils can help manage many pests.
Dahlias are also susceptible to diseases. Powdery mildew, a white, powdery coating on leaves, is common in warm, humid conditions. Ensure good air circulation by proper spacing and removing lower leaves to prevent it. Botrytis blight (gray mold) causes brown spots on flowers and leaves, particularly in damp weather. Viral issues, characterized by mottled or distorted leaves, can be spread by insects like aphids; unfortunately, there is no cure for most viral diseases.
If dahlias fail to bloom, insufficient sunlight is a common cause, as dahlias require abundant light. Over-fertilizing with nitrogen can promote lush leafy growth at the expense of flowers. Consistent deadheading is also important, as spent blooms divert energy from new flower production.
Leggy growth, long stems with sparse foliage, indicates insufficient light. Move the plant to a sunnier location to resolve this. Pinching back young dahlia plants at 12-16 inches tall encourages bushier growth and more branching, leading to a sturdier plant with increased bloom potential.