Dahlia ‘Castillo’ is a captivating variety known for its striking appearance and rewarding blooms, making it a popular choice for gardeners seeking to add rich color and form to their outdoor spaces. It offers a blend of beauty and manageability, appealing to both experienced cultivators and those new to growing dahlias.
Dahlia ‘Castillo’ Characteristics
Dahlia ‘Castillo’ features deep red, often wine-red, blooms. These flowers typically exhibit a formal decorative or double form, creating a full appearance. Bloom size generally ranges from 3 to 4 inches in diameter, providing a substantial floral impact without being excessively large.
The plant maintains a compact, upright growth habit, usually reaching 15 to 18 inches tall with a similar spread. This moderate size suits various garden applications, including containers, borders, and mixed beds. Dahlia ‘Castillo’ flowers continuously from planting until the first frost.
Planting Your Dahlia ‘Castillo’
Plant Dahlia ‘Castillo’ tubers in spring, after all danger of frost has passed and the soil temperature has warmed to at least 55-60°F. This often aligns with outdoor tomato planting, typically mid-May. For earlier blooms, tubers can be started indoors in pots about a month prior.
Dahlias need ample sunlight, ideally six to eight hours daily. Well-draining soil is crucial, as tubers are prone to rot in cold, wet conditions. Enriching the soil with compost or organic fertilizer before planting promotes robust growth and healthy blooms.
When planting, dig a hole 4 to 6 inches deep, placing the tuber horizontally with the “eye” facing upwards. Space tubers 12 to 18 inches apart for adequate growth and air circulation. After covering, avoid heavy watering until green shoots emerge, as too much moisture can lead to tuber rot.
Caring for Dahlia ‘Castillo’
Once established, provide consistent and deep watering, aiming to provide enough moisture to reach the tuber’s root zone, typically 8-10 inches deep. In average conditions, watering two to three times per week should suffice, but in hot or dry climates, daily watering may be necessary, especially for dahlias in containers.
Once plants begin to bloom, feed every other week with a balanced, low-nitrogen fertilizer, such as a fish and seaweed formula, to encourage more flowers. Avoid high-nitrogen fertilizers, which promote leafy growth over blooms.
For taller plants, staking prevents flopping, especially in wind or rain. Insert stakes at planting time to avoid tuber damage. Deadhead spent blooms to redirect energy from seed production to new flowers, promoting a longer season. Regularly inspect plants for pests like aphids, spider mites, slugs, and thrips, and diseases such as powdery mildew or botrytis, addressing issues promptly.
Overwintering Dahlia ‘Castillo’
In climates with freezing winters (USDA Zones 8 and below), Dahlia ‘Castillo’ tubers are not hardy and must be dug up and stored indoors to survive the cold season. In warmer, frost-free regions (USDA Zones 9-11), tubers can often remain in the ground if soil is well-drained.
After the first hard frost, which causes the foliage to turn brown and die back, wait one to two weeks before digging up tubers. This period allows the tubers to cure and develop “eyes,” which are vital for next year’s growth. Carefully lift clumps, gently removing excess soil. Some growers wash tubers, while others store them with soil attached.
Once cleaned, dry tubers for a few days in a cool, dark, well-ventilated area, ensuring they don’t freeze during this curing process. Proper storage involves placing the dried tubers in a medium like peat moss, vermiculite, or wood shavings in a container such as a cardboard box or plastic crate. The ideal storage temperature is 40-45°F, with 75-85% relative humidity. Check tubers periodically, removing any showing rot or excessive shriveling.