Dahlia Decorative Blue Boy (Pack of 2)

Dahlia Decorative ‘Blue Boy’

The Blue Boy Decorative Dahlia delivers stunning lavender-blue blooms that bring refreshing contrast and elegance to the summer and fall garden. Often referred to as the Blue Boy Dahlia, Dahlia Blue Flower, or Dahlia Blue Boy, this variety is cherished for its cool-toned blossoms and perfectly formed, double-petaled heads. Each flower measures approximately 4–6 inches across and sits atop a sturdy, upright stem—perfect for cutting gardens, mixed borders, and container plantings. Its saturated coloring is especially striking when paired with warm-hued companions, creating dynamic seasonal displays that evolve from mid-summer through the first frost.

• USDA Zones: 8–10 (other zones must lift for the winter)
• Bloom Time: Summer–Fall
• Height: 36"
• Planting depth/Spacing: 2–4"/18"
• Deer Resistant: No

To learn more about the dahlias’ upkeep and maintenance, please visit our blogs and videos below.

It offers rich visual texture and extended seasonal performance. Its long bloom season, coupled with lush, blue-violet tones, makes it a favorite among designers and flower lovers. Whether planted en masse or woven into a mixed border, it elevates the beauty of the landscape with both form and function.

Key Characteristics and Benefits of Blue Boy Dahlia

• Rare Coloration: Lavender-blue petals add a cooling effect to garden palettes.
• Cut Flower Favorite: Long, strong stems and large blooms make it ideal for floral arrangements.
• Extended Blooming Period: Blooms from mid-summer until the first frost.
• Pollinator Support: Attracts bees and beneficial insects.
• Garden Versatility: Excellent in borders, containers, and cutting gardens.

Growing Dahlia Blue Boy Tubers

Plant Dahlia Decorative Blue Boy tubers in spring after the threat of frost has passed. Choose a sunny location with well-draining soil and work in compost to enrich the planting site. Space tubers 18 inches apart, planting 2–4 inches deep. Provide consistent watering during dry periods, and stake stems to support heavy blooms throughout the growing season.

Climate and Soil Requirements

Dahlias thrive in USDA zones 8–10. In colder zones, tubers should be lifted in fall and stored indoors. Grow in fertile, loose soil with excellent drainage to avoid rot.

Sunlight and Watering

Plant in full sun (6–8 hours daily). Water deeply once or twice a week, allowing soil to slightly dry between waterings. Avoid wetting foliage to reduce disease risk.

Care and Maintenance

Pinch young plants to encourage branching. Deadhead regularly to promote continuous flowering. In cold regions, lift tubers after the first frost, clean and store in a cool, dry place for replanting next season.

For more tips on caring for flower bulbs, explore our complete Flower Bulb Growing Guide .

Multiple Trusted Brands at Grow Organic

At Grow Organic, we proudly source Dahlia Decorative Blue Boy from a curated selection of high-quality, reputable growers. This gives our customers the flexibility to choose from multiple trusted brands and ensures healthy, viable tubers suited for successful growing in a range of garden settings.

Companion Planting Ideas

Pair it with other late-season performers like Rudbeckia, Cosmos, or Coreopsis. For a cool-themed planting scheme, combine with white or pink dahlias and soft silver-foliage plants. For floral bouquets, blend with lisianthus, hydrangeas, or statice for elegant texture and balance.

More Dahlia Inspiration and Resources

Looking to improve your dahlia-growing skills? Check out our guide on Growing Summer-Blooming Flowers: Dahlias for planting tips, seasonal care, and cutting techniques.

Enhance your garden’s seasonal color and support local pollinators with vibrant blooms from our Annual Flower Seeds Collection.