Dahlias are a gardener’s favorite, blooming from mid-summer until frost. The ‘Coco Dahlia’ is a captivating variety, cherished for its striking color and classic shape, making it a dramatic focal point or cut flower. This guide will help you cultivate and care for this beautiful dahlia.
What is a Coco Dahlia?
The ‘Coco Dahlia’ is known for its deep, rich coloration, typically dark burgundy, deep red, or almost black, providing dramatic contrast. Its blooms are often decorative, with orderly, broad petals that are flat or slightly incurved, commonly reaching 6 to 8 inches across. This dahlia exhibits an upright growth habit, reaching 3 to 4 feet tall with a 1 to 2-foot spread. Its sturdy stems support the large flowers, though taller plants may need support. The ‘Coco Dahlia’ maintains its color depth even in strong sunlight, making it a striking garden addition.
Planting Your Coco Dahlia
Selecting the right location is crucial for ‘Coco Dahlias’, as they thrive in full sun, requiring at least six to eight hours of direct sunlight daily. Protection from strong winds is also beneficial to prevent stem breakage. The soil should be well-draining and rich in organic matter, with a slightly acidic pH between 6.5 and 7.0. Amending heavy clay soils with compost can improve drainage and texture.
Before planting, inspect tubers, discarding any soft, shriveled, or damaged ones. Plant ‘Coco Dahlia’ tubers after the last spring frost, when soil temperatures consistently remain above 60°F (mid-April through May, depending on region). Dig a 4 to 6-inch deep hole, placing the tuber horizontally with the “eye” or sprout facing upwards. Space multiple tubers 12 to 18 inches apart for air circulation. After covering with a few inches of soil, water thoroughly to settle it, but avoid further watering until shoots emerge to prevent rot.
Ongoing Care for Coco Dahlias
Consistent moisture is important once ‘Coco Dahlias’ begin to grow, especially during dry spells. After shoots appear, deep watering three to four times per week is recommended, ensuring water penetrates 8 to 10 inches deep. While initial watering after planting is minimal, established plants require more frequent watering; container plants may need daily attention.
Dahlias benefit from balanced fertilizer throughout the growing season. A low-nitrogen fertilizer, such as a 5-10-10 NPK ratio, is recommended to encourage blooms over foliage. Apply fertilizer according to product instructions, usually every few weeks once plants are established and actively blooming.
Tall ‘Coco Dahlia’ plants, especially those over 3 feet, require staking to support heavy blooms and prevent stem breakage. Install stakes at planting time, about 3 inches from the tuber. As the plant grows, tie main stems loosely to the stake every 12 inches, allowing movement while providing support.
Monitor for pests and diseases. Common pests include aphids, slugs, earwigs, and spider mites. Organic solutions like insecticidal soaps or neem oil manage aphids and spider mites, while hand-picking or copper barriers are effective against slugs. Good air circulation, achieved through proper spacing and pruning, helps prevent fungal issues like powdery mildew and botrytis blight. Promptly remove affected plant parts and consider a baking soda solution for powdery mildew.
Pruning and Deadheading
Pinching or topping young ‘Coco Dahlia’ plants encourages bushier growth and more prolific flowering. When the plant reaches about 1 foot tall or has three to four leaf sets, pinch off the central growing tip just above the third or fourth leaf set. This stimulates lateral branches, resulting in a fuller plant with more blooms.
Deadheading, the removal of spent flowers, maintains aesthetic appeal and promotes continuous blooming. Cut the flower stem back to a strong leaf joint or side shoot with new growth. This prevents the plant from expending energy on seed production, redirecting it to new flowers.
Formative pruning involves removing weak, crossing, or inward-growing stems to improve air circulation and reduce fungal disease risk. Regularly inspecting and selectively removing such stems enhances plant health and bloom quality. Removing lower leaves also improves air flow at the plant’s base, deterring pests.
Winterizing and Storing Tubers
In regions with freezing winters, ‘Coco Dahlia’ tubers are not hardy and must be dug up and stored indoors. The ideal time to dig tubers is after the first hard frost blackens the foliage, but before the ground freezes. Waiting a week or two after the frost allows tubers to cure slightly in the ground, toughening their skins for storage.
To dig, cut the main stem back to 4 to 6 inches above ground, using it as a handle. Carefully loosen soil around the tuber clump with a garden fork, starting 8 to 10 inches from the stem to avoid damage. Gently lift the clump, brushing off excess dirt. Avoid washing tubers immediately, as moisture promotes rot.
After digging, allow tubers to dry for a few days in a cool, dry location away from direct sunlight. Once dry, clean off remaining soil and trim fine roots or damaged sections. Store tubers in a cool, dark, frost-free environment with consistent temperatures between 40-50°F and moderate humidity (80-90%). Common storage mediums include peat moss, vermiculite, or wood shavings; ensure tubers are not touching to prevent rot spread. Periodically inspect stored tubers, removing any showing rot or shriveling, and lightly misting the medium if tubers appear too dry.