Dahlia ‘Sebastian’ offers a captivating display for gardeners, bringing vibrant color and unique charm to any landscape. Its distinct blooms and relatively easy-growing disposition make it a favored choice, providing months of visual interest throughout the summer season.
Understanding Dahlia Sebastian
Dahlia ‘Sebastian’ has a formal decorative bloom shape, characterized by a profusion of petals. The flowers measure around 3 inches in diameter, showcasing a warm melon color that transitions into a peach-lavender or rich copper hue towards the center. Some descriptions highlight light salmon petals at the edges, deepening to more purple tones at the core.
This dahlia cultivar reaches a height of 36 to 40 inches (70 cm to 1 meter) and maintains an upright habit with a spread of 12 to 20 inches (30 to 50 cm). It produces numerous flowers excellent for cutting and creating arrangements, further enhanced by its darker stems and foliage.
Planting and Establishing Dahlia Sebastian
Plant tubers outdoors in spring after the last frost, when the soil temperature reaches 60°F (15°C). Gardeners in cooler climates can gain a head start by planting tubers indoors in pots four to six weeks before the anticipated outdoor planting date.
Dahlia ‘Sebastian’ thrives in full sun, receiving six to eight hours of direct sunlight daily, especially morning sun. The soil should be well-drained, rich in organic matter, and have a pH between 6.0 and 7.5. Before planting, loosen the soil to a depth of 8 to 12 inches and incorporate compost or aged manure to improve drainage and nutrient content.
Dig a hole 3 to 6 inches deep and place the tuber with the “eye” facing upwards. Space tubers 12 to 18 inches apart. After planting, water sparingly until the first sprouts emerge, as overwatering can lead to tuber rot. Once green shoots are visible, begin regular watering.
Ongoing Care for Dahlia Sebastian
Once established, Dahlia ‘Sebastian’ requires consistent care for vigorous blooming. Water deeply one to three times per week, ensuring moisture penetrates at least eight inches into the soil. Let the top inch of soil dry out between waterings and avoid wetting the foliage to minimize disease risk.
Begin fertilization once plants reach 12 inches in height, with applications every three to four weeks throughout the growing season. A low-nitrogen fertilizer, such as a 5-10-10 ratio, is recommended to promote flower production over excessive foliage growth. Avoid high-nitrogen formulas.
Staking is recommended for Dahlia ‘Sebastian’ due to its height and large blooms, preventing stems from bending or breaking. Insert sturdy stakes, such as bamboo or metal rods, at planting time to avoid damaging the tubers. As the plant grows, gently tie the stems to the stakes every foot or so using soft garden twine.
Regular deadheading, the removal of spent blooms, is important for encouraging continuous flowering and maintaining the plant’s appearance. Snip faded flowers just above the nearest set of healthy leaves or buds. Common pests like slugs, snails, earwigs, and aphids can affect dahlias; manage these issues with bait, traps, neem oil, or insecticidal soap.
Overwintering Dahlia Sebastian
For gardeners in USDA zones 3 to 7, Dahlia ‘Sebastian’ tubers need to be lifted and stored for winter. This should occur after the first killing frost blackens the foliage, but before the ground freezes, in late fall (October or November).
Begin by carefully digging around the dahlia clump with a fork or shovel, taking care not to damage the tubers. Gently shake off excess soil from the tubers. Some gardeners choose to rinse the tubers clean with water, while others prefer to leave some soil attached.
After cleaning, allow the tubers to dry for one to two days in a cool, dark location with good airflow, such as a garage or basement, until they are dry to the touch. Once dry, store the tubers in a frost-free environment with a consistent temperature between 40-50°F (4-10°C) and a relative humidity of 75-85%. Tubers can be stored in a medium like peat moss, vermiculite, or dry compost to maintain appropriate moisture levels and prevent rot or desiccation. They can be placed in cardboard boxes, paper bags, or crates, ensuring they are not touching each other if possible. Regularly inspect stored tubers every few weeks to remove any that show signs of rot or shriveling.