Dahlia ‘Baccara’ is a highly sought-after choice for gardeners, celebrated for its striking appearance and ability to serve as a captivating focal point in garden beds and floral arrangements. Its popularity stems from its deep, velvety red color and classic dahlia form, which contribute to a dramatic and elegant display. This variety is particularly appealing for those looking to add rich color to their landscape or create stunning cut flower bouquets.
Distinctive Features of Dahlia Baccara
Dahlia ‘Baccara’ blooms are a true burgundy, a rich, velvety crimson without any hint of purple. This deep hue contrasts with the plant’s dark, black-green foliage, creating a dramatic visual impact.
The semi-double flowers have slightly pointed petals, classifying them as Decorative Dahlias (Group 5). These blooms typically measure about 14 centimeters (5.5 inches) across. The plant grows to 90 to 120 centimeters (3 to 4 feet) tall, making it suitable for the middle or back of a border, or as a specimen in containers.
Cultivating and Caring for Dahlia Baccara
Dahlia ‘Baccara’ thrives in full sun, needing at least six to eight hours of direct sunlight daily. In hot climates, afternoon shade can prevent heat stress and protect blooms.
They require well-draining soil rich in organic matter, with an ideal pH between 6.0 and 7.5. For heavy clay, amend with compost, aged manure, peat moss, or sand to improve drainage and aeration. This prevents tubers from sitting in waterlogged conditions, which can cause rot.
Consistent moisture is important, but avoid overwatering. After planting tubers, water once thoroughly, then wait for shoots to emerge before watering again. Once established, deep water one to three times a week, ensuring water penetrates 6-10 inches. Drip irrigation or soaker hoses are beneficial as they keep foliage dry, deterring fungal diseases. Container-grown dahlias may need daily watering.
Dahlia ‘Baccara’ are heavy feeders. Use a low-nitrogen fertilizer, higher in phosphorus and potassium (e.g., 5-10-10 or 2-4-4). High nitrogen promotes leafy growth over blooms. Apply fertilizer about 30 days after planting, continuing every three to four weeks until September. Stop fertilizing in September to prepare tubers for overwintering.
The ideal temperature for dahlia growth is 15.5°C to 27°C (60°F to 80°F). Stable temperatures are preferred, with daytime temperatures between 21-27°C (70-80°F) and nighttime temperatures between 15.5-21°C (60-70°F). Temperatures above 29°C (85°F) can cause stress, leading to stunted growth or misshapen blooms. Soil temperature must reach at least 15°C (60°F) before planting tubers.
Planting and Ongoing Maintenance
Plant Dahlia ‘Baccara’ tubers outdoors after the last spring frost, once soil temperature consistently reaches 15°C (60°F). For an earlier start, pot tubers indoors four to six weeks before the last frost, then transplant outside.
Prepare the planting site by loosening soil to at least 30 centimeters (12 inches) deep. Dig a 15 to 20 centimeter (6 to 8 inch) deep hole, placing the tuber horizontally with the “eye” facing up. Position the tuber top 7.5 to 15 centimeters (3 to 6 inches) below the soil surface. Cover with a few inches of soil, then gradually fill the rest as the plant grows, ensuring no air pockets.
Space tubers 30 to 45 centimeters (12 to 18 inches) apart for proper air circulation. Due to their height, staking is recommended to support stems and prevent breakage. Install stakes at planting time to avoid damaging tubers later. Tie main stems to the support when the plant is about 30 centimeters (12 inches) tall, adding more ties as it grows.
Pinch the central stem when the plant is 30 to 40 centimeters (12 to 16 inches) tall with three to five sets of leaves. Remove the uppermost sprout with clean pruners or fingers. This encourages bushier growth and more blooms, though it may delay the first flowers by a week or two.
Regular deadheading, removing spent flowers, is essential for continuous blooming. This prevents the plant from producing seeds, redirecting energy to new buds. Cut spent blooms at the intersection of their stem and the first healthy leaves below, using sharp, clean tools. Consistent deadheading ensures vibrant blooms from mid-summer until the first hard frost.
Common Challenges and Overwintering
Dahlia ‘Baccara’ can face pests and diseases. Common pests include aphids, which cause stunted growth and distorted leaves and can be managed with insecticidal soaps or neem oil. Slugs and earwigs may chew on foliage and buds; keeping the garden tidy and using barriers or traps can help deter them. Spider mites thrive in hot, dry conditions, leading to mottled leaves, and can be combated by spraying with water or horticultural oils.
Diseases include:
Powdery mildew: White fungal growth in humid conditions; improve air circulation and keep foliage dry.
Root rot: Occurs in waterlogged soil; ensure proper drainage.
Dahlia Mosaic Virus: Causes distorted growth and discolored leaves; remove and destroy infected plants to prevent spread, as there is no cure.
Soft rot: Bacterial disease causing wilting and mushy stems; promptly remove affected plants.
For colder climates, overwintering tubers ensures their return. Lift tubers after the first hard frost blackens foliage, typically one to two weeks after a killing frost. Cut stalks to 10-15 centimeters (4-6 inches) before gently digging around the plant, avoiding tuber damage.
After lifting, shake off excess soil. Some growers rinse tubers, others do not to prevent mold. If washed, dry and cure tubers for several days in a cool, well-ventilated area away from direct sunlight, turning them upside down to drain hollow stems. Remove any damaged or rotten parts before storage.
Store cleaned, cured tubers in a cool, dark, frost-free location between 4.5°C and 10°C (40°F and 50°F). They need 80-90% humidity to prevent shriveling, but too much moisture can cause rot. Pack tubers in peat moss, vermiculite, or wood shavings within ventilated cardboard boxes, paper bags, or plastic bins. Periodically check tubers throughout winter, discarding any showing rot or excessive shriveling.