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Dahlia

Common Name(s):

Previously known as:

  • Dahlia x hortensis
Phonetic Spelling
DAHL-ee-a
This plant has low severity poison characteristics.
See below
Description

Dahlias are herbaceous perennials in the aster family (Asteraceae) that are native to Mexico, Central America, and northern South America. The genus is named after Anders Dahl, a Swedish botanist who died in 1789. Dahlias have an erect form and a rapid growth rate and are generally considered high maintenance.

Dahlias need fertile, moist but well-drained soil, and full sun to partial shade. These plants are most often grown as annuals as their tuberous roots can be injured at temperatures below 25 degrees F. Despite their tropical origins, dahlias may languish during the heat of summer. Keep them mulched and provide plenty of water, and they will reward you with a long bloom season, from late summer to first frost. Deadhead spent flowers to extend blooming. Dahlias tend to be tall and may require staking. 

To grow dahlias as perennials in zones below 7, dig up the tubers in fall, dry carefully (do not wash), and store in vermiculite or dry sand at 35 to 45 degrees F. In zones 7 to 10, mulch over in winter. When planting, cover tubers to a depth of 3 inches. Propagation is by division or root cutting. Dahlias can also be grown from seed-germinated selections, but these are typically dwarfs, often not heat tolerant, and are poor bloomers.

The American Dahlia Society recognizes 29 groups based on flower size and shape, including single, anemone, collarette, waterlily, decorative, fall, pompon, cactus, semi-cactus. There are 41 accepted species of dahlias in an array of flower colors, sizes, and shapes, but cultivated dahlias are hybrids of mixed parentage.

Dahlias are at home in cottage, cutting, or container gardens. Add them to a border, as an accent or planted in small groups. They attract bees, butterflies, and hummingbirds. 

Insects, Diseases, and Other Plant Problems: Dahlias are susceptible to phytophthora blight and root rot, powdery mildew, crown gall, viruses, and wilts. They may also be hampered by aphids, leafhoppers, and caterpillars.  

VIDEO Created by Elisabeth Meyer for "Edibles, Bulbs, and Houseplants" a plant identification course offered in partnership with Longwood Gardens.   

Profile Video:
See this plant in the following landscapes:
Pollinator and Culinary Garden Flower Bonanza Garden
Cultivars / Varieties:
  • 'Mystic Enchantment'
    Red blooms
  • 'Peaches And Dreams'
'Mystic Enchantment', 'Peaches And Dreams'
Tags:
#showy flowers#poisonous#heat tolerant#houseplant#accent plant#window boxes#border planting#bedding plants#cutting garden#fantz#small group plantings#problem for cats#ebh#problem for dogs#problem for horses#ebh-g#contact dermatitis#container plant#perennial#buncombe county sun and shade garden#cpp
 
Cultivars / Varieties:
  • 'Mystic Enchantment'
    Red blooms
  • 'Peaches And Dreams'
'Mystic Enchantment', 'Peaches And Dreams'
Tags:
#showy flowers#poisonous#heat tolerant#houseplant#accent plant#window boxes#border planting#bedding plants#cutting garden#fantz#small group plantings#problem for cats#ebh#problem for dogs#problem for horses#ebh-g#contact dermatitis#container plant#perennial#buncombe county sun and shade garden#cpp
  • Attributes:
    Genus:
    Dahlia
    Family:
    Asteraceae
    Life Cycle:
    Perennial
    Recommended Propagation Strategy:
    Division
    Root Cutting
    Country Or Region Of Origin:
    Mexico, Central America, northern South America
    Wildlife Value:
    attracts butterflies, bees, and hummingbirds.
    Bulb Storage:
    In Zone 7 harvest tuberous roots in fall, dry carefully (do not wash), and store in vermiculite or dry sand at 35-45 degrees F. In Zone 8, just mulch.
    Edibility:
    Were grown as a food crop by Aztecs, but the practice has died out.
    Dimensions:
    Height: 1 ft. 0 in. - 6 ft. 0 in.
    Width: 1 ft. 0 in. - 3 ft. 0 in.
  • Whole Plant Traits:
    Plant Type:
    Annual
    Bulb
    Herbaceous Perennial
    Poisonous
    Woody Plant Leaf Characteristics:
    Deciduous
    Habit/Form:
    Erect
    Growth Rate:
    Rapid
    Maintenance:
    High
  • Cultural Conditions:
    Light:
    Full sun (6 or more hours of direct sunlight a day)
    Partial Shade (Direct sunlight only part of the day, 2-6 hours)
    Soil Texture:
    High Organic Matter
    Soil Drainage:
    Good Drainage
    Moist
    Available Space To Plant:
    12 inches-3 feet
    NC Region:
    Coastal
    Mountains
    Piedmont
    USDA Plant Hardiness Zone:
    7a, 7b, 8a, 8b, 9a, 9b, 10a, 10b
  • Flowers:
    Flower Color:
    Cream/Tan
    Gold/Yellow
    Orange
    Pink
    Purple/Lavender
    Red/Burgundy
    Variegated
    White
    Flower Inflorescence:
    Corymb
    Head
    Flower Value To Gardener:
    Good Cut
    Long Bloom Season
    Showy
    Flower Bloom Time:
    Fall
    Summer
    Flower Petals:
    Bracts
    Flower Description:
    Flowers are highly variable but consistently have reflexed involucral bracts at the base. Flowering heads are usually large (ranging from 2 to 12 inches), with many florets, variously colored. They bloom from mid-summer to mid-fall, showy and excellent in flower arrangements. Axillary, 1 to 3 heads in a corymb; head oriented vertical, 2-12" diam., aster to double forms. Disc and ray flowers variable in color. Garden origin.
  • Leaves:
    Woody Plant Leaf Characteristics:
    Deciduous
    Leaf Color:
    Green
    Purple/Lavender
    Red/Burgundy
    Leaf Type:
    Compound (Pinnately , Bipinnately, Palmately)
    Simple
    Leaf Arrangement:
    Opposite
    Leaf Shape:
    Lanceolate
    Oblong
    Ovate
    Leaf Margin:
    Dentate
    Lobed
    Serrate
    Hairs Present:
    No
    Leaf Description:
    Opposite, simple (terminal leaflet) to 3-5-7-pinnately compound, segments ovate to oblong to lanceolate. Margins may be lobed or dentate. Simple leaves are more common towards the top of the plant while compound leaves are more common at the base. Leaves may be green or reddish-purple.
  • Stem:
    Stem Color:
    Brown/Copper
    Red/Burgundy
    Stem Is Aromatic:
    No
  • Landscape:
    Landscape Location:
    Container
    Houseplants
    Landscape Theme:
    Children's Garden
    Cottage Garden
    Cutting Garden
    Pollinator Garden
    Design Feature:
    Accent
    Border
    Mass Planting
    Small groups
    Attracts:
    Bees
    Butterflies
    Hummingbirds
    Problems:
    Contact Dermatitis
    Poisonous to Humans
    Problem for Cats
    Problem for Dogs
    Problem for Horses
  • Poisonous to Humans:
    Poison Severity:
    Low
    Poison Symptoms:
    Foliage is toxic if eaten in large quantities. Skin irritation following repeated handling of the tubers and contact with leaves and sunlight (phototoxicity). Mild gastrointestinal signs.
    Poison Toxic Principle:
    Phototoxic polyacetylene compounds
    Causes Contact Dermatitis:
    Yes
    Poison Part:
    Leaves