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'
- 'Mystic Enchantment', 'Peaches And Dreams'
- Tags:
- Cultivars / Varieties:
-
- 'Mystic Enchantment'
Red blooms - 'Peaches And Dreams'
- 'Mystic Enchantment'
- 'Mystic Enchantment', 'Peaches And Dreams'
- Tags:
-
-
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:
- Coastal
- Container
- Hanging Baskets
- Meadow
- Near Septic
- Patio
- Pool/Hardscape
- Recreational Play Area
- Slope/Bank
- Small Space
- Walkways
- 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
