Scientific Name
Dahlia imperialis Roezl ex Ortgies
Common Name(s)
Bell Tree Dahlia, Tree Dahlia, Giant Dahlia, Imperial Dahlia, Species Tree Dahlia
Synonym(s)
Dahlia dumicola, Dahlia lehmannii, Dahlia maximiliana, Dahlia maximiliana, Dahlia maxonii
Scientific Classification
Family: Asteraceae
Genus: Dahlia
Flower
Color: Lavender or mauvish-pink
Bloom Time: Late fall
Description
Dahlia imperialis is a fast-growing, tuberous, herbaceous perennial up to 33 feet (10 m) tall, rapidly growing from the base after a dormant winter period, developing brittle, cane-like, 4-angled stems with swollen nodes and large tripinnate leaves, those near the ground soon being shed.
The pendant or nodding flower heads are up to 6 inches (15 cm) across with ray florets lavender or mauvish-pink in color.
How to Grow and Care
Feed Dahlias about once a month with organic fertilizer, lower in nitrogen and higher in phosphorus and potassium, such as a 1-2-2 ratio. With enough compost, your Dahlias will do fine without fertilizer. Make sure your Dahlias get an inch of water per week. Keep track of rainfall so that the water is consistent.
Clip off spent blossoms to encourage more blooming. While optional, some gardeners remove many of the flower buds to focus the plant's energy on fewer, larger, and showier blooms with long stems. The flower buds come in clusters of three. If desired, remove the two side buds, allow the middle one to grow, and keep pinching off any more side buds that form along the end of the stem.
For a more natural look, pinch back Dahlia plants when small to encourage branching. Dahlias can be divided into fall or spring. Dig up the tubers and use a sharp knife to cut them into sections, ensuring each section has at least one eye. Allow tubers to dry overnight before replanting.
If Dahlias are hardy in your zone, cut them back after the first heavy frost and apply an extra layer of mulch to protect them from the cold. Remove the extra mulch in spring. Dig up and store the tubers in a basement or garage in colder climates, then divide and replant them in the spring.
See more at How to Grow and Care for Dahlia.
Origin
Dahlia imperialis is native to Mexico, Central America, and Colombia.
Links
- Back to genus Dahlia
- Plantpedia: Browse flowering plants by Scientific Name, Common Name, Genus, Family, USDA Hardiness Zone, or Origin
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