36-40" tall. Dahlia Blue Boy is a show-stopping lilac-blue variety that brings a unique color to the world of Dahlias. These well-formed flowers provide dramatic color in flower beds and borders for many months from midsummer. Mix Blue Boy with shades of pink, purple or silver for an outstanding display, or use it to cool down warmer colored flowers. Cold hardy in zones 8-10. In colder zones lift the bulbs in fall and store in a cool place over the winter.
Blue Boy Dahlia
Dahlia Blue Boy
Item Package Size
Bag of 3
Mid summer until frost
1 bulb / tuber per sq. ft.
Bulbs/Tubers should be planted 1" to 2" below the soil line.
Attract Butterflies, Attract Hummingbirds, Extended Bloom Time (more than 4 weeks), Easy To Grow, Good For Cut Flowers, Good For Containers
Can be grown as annuals in zones 3-7. Hardy in zones 8–10.
8, 9, 10
Bulb, Rhizome, Tuber
Poisonous or Toxic to Animals
Tubers and leaves are toxic if eaten in large amounts.
Spring / Summer
Ships To Canada
Summer Blooming Bulbs, including popular varieties such as gladiolus and dahlias, are planted in the spring and bloom in the summer. Most of these bulbs are tropical and require warm weather to be planted. There must not be any danger of frost and your ground temperature must have reached 55 degrees Fahrenheit before planting. Many
of our summer blooming bulbs can be planted as perennials in zones 9-10 (zone 8 if mulched), but should be treated as annuals in cooler climates. You can lift them and store them in the fall, or bring patio pots inside before frost. See page 15 of our Planting Guide for a bulb depth planting illustration. Read our article about How To Grow Dahlias.
Growing Dahlias: Plant Dahlia tubers after spring frosts in good garden soil with full sun. Dahlias must be protected from high winds, so we suggest you position them against a wall or be ready to stake them. Keep the plants well-watered and free of bugs, applying flower fertilizer as they grow. Your dahlias will be in full bloom by July or August, with the enormous flowers continuing to bloom until frost. As frost threatens, pull up the roots and trim off the stems. You can store the tubers in a cool dry place until the following spring.
View more Planting Guides, or download our complete Planting Guide for tips on caring for your plants when you receive your order, as well as planting instructions for Perennials, Spring-Planted Bulbs, Fall-Planted Bulbs, Cacti & Succulents, Xeric Plants and more.
As soon as your order is placed you will receive a confirmation email. You will receive a second email the day your order ships telling you how it has been sent. Some perennials are shipped as potted plants, some as perennial roots packed in peat. The ‘Plant Information’ section describes how that item will ship. All perennials and spring-planted bulbs are packaged to withstand shipping and are fully-guaranteed. Please open upon receipt and follow the instructions included.
Perennials and spring-planted bulbs are shipped at the proper planting time for your hardiness zone. Perennial and spring-planted bulb orders will arrive separately from seeds. If your order requires more than one shipment and all items are shipping to the same address, there is no additional shipping charge. See our shipping information page for approximate ship dates and more detailed information. If you have any questions, please call Customer Service toll-free at (800) 925-9387 or contact us by email.
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