Dahlia ‘Rosella’ is a garden favorite, admired for its impressive blooms and elegant presence. Its popularity stems from its abundant, captivating flowers that can transform any garden space into a vibrant display. This variety is cherished by gardeners for its dramatic color and form, making it a highly sought-after choice for both beds and cut flower arrangements.
Dahlia Rosella Characteristics
Dahlia ‘Rosella’ is known for its magnificent, large blooms, often categorized as dinnerplate dahlias, reaching up to 10 inches (25 cm) in diameter. These fully double flowers display lilac-pink or purplish-pink hues, creating a striking visual impact. The petals are typically tongue-shaped with sharp tips, sometimes twisting inwards or waving slightly. The robust plant grows to 44 to 55 inches (1.1 to 1.4 meters) tall, with mid-green pinnate leaves and ovate leaflets.
Planting Dahlia Rosella
Planting Dahlia ‘Rosella’ tubers begins in spring, after frost has passed and the soil has warmed. This timing generally coincides with when it is safe to plant tomatoes. An ideal location provides full sunlight (at least six hours daily) and shelter from strong winds.
The soil should be well-drained, fertile, and rich in organic matter. While ‘Rosella’ tolerates various soil types (acidic, clay, loamy, sandy), good drainage is necessary to prevent tuber rot. Amending the planting site with compost or aged manure before planting enhances soil structure and fertility.
Place tubers approximately 2 to 6 inches (5 to 15 cm) deep in the soil, with the “eye” or growth point facing upwards. Space tubers 18 to 24 inches (45 to 60 cm) apart for mature plant development. After planting, avoid immediate heavy watering unless the soil is exceptionally dry. It is best to wait until green shoots emerge from the soil, as tubers do not absorb water directly, and excessive moisture before root development can lead to rot.
Ongoing Care for Dahlia Rosella
Once Dahlia ‘Rosella’ plants are established and actively growing, consistent watering is important for robust development and abundant blooms. Deep watering two to four times per week is generally recommended, especially during hot, dry periods, to ensure moisture reaches the deeper root system. Watering at the base of the plant rather than overhead helps keep foliage dry, reducing the risk of fungal diseases like powdery mildew.
Dahlias benefit significantly from regular fertilization throughout their growing season. After initial soil preparation, apply a general-purpose fertilizer or a high-potash formula every few weeks during summer to support continuous blooming. Removing spent flowers (deadheading) also encourages more blooms and extends the flowering period.
Due to their height and large, heavy flowers, Dahlia ‘Rosella’ plants typically require staking or other support to prevent stems from bending or breaking. Install support structures, such as stakes or tomato cages, at planting time to avoid damaging tubers later. Vigilance against common pests like aphids, slugs, snails, and spider mites is also part of routine care. Maintaining good air circulation and a clean garden area helps prevent issues, while organic pest control methods can address outbreaks.
Overwintering Dahlia Rosella
In regions with cold winters, Dahlia ‘Rosella’ tubers are not winter-hardy and must be lifted for storage. This process typically occurs after the first hard frost, which signals the end of the growing season and causes foliage to die back. Carefully dig up the entire tuber clump, taking care not to damage the tubers.
After lifting, gently brush off excess soil. Some gardeners wash tubers, while others leave a small amount of dirt, but thorough drying is important. Air-dry tubers in a warm, well-ventilated area for several days (24 hours to a few days) before storage.
Store cleaned, dried tubers in a cool, dark, frost-free location at 40-45°F (4-7°C). Maintain 75-85% relative humidity to prevent desiccation or mold. Acceptable storage mediums include dry peat moss, vermiculite, or coarse sand, which regulate moisture. Place tubers in crates with good airflow or plastic containers with ventilation holes to ensure viability until spring.