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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 the darlings of the late summer garden. Visit any county or state fair in the autumn and you will likely find dozens of dahlias. The array of flower colors, sizes, and shapes is astounding. Check out the American Dahlia Society website for the many classifications and colors.

There are 42 accepted species of dahlias available in almost any color:  white, shades of pink, red, yellow, orange, shades of purple, and various combinations of these colors. Some of the flower forms are truly amazing, from the charming single, daisy-like flowers to the popular double varieties which can range from the 2-inch-pompons to 12 inches across. They are divided into ten groups: single, anemone, collarette, waterlily, decorative, fall, pompon, cactus, semi-cactus and miscellaneous.  Some of the most spectacular are the peony and cactus forms.

Any garden with fertile, well-drained soil and lots of sun can become a home to dahlias. Since all garden dahlias are hybrids, they are most often planted as tuberous roots. Seeds are available for mixed, small-flowered types. Plant the tuberous roots or plants about the time of the last frost date, 1 to 3 feet apart depending on the variety. They look best planted in groups of at least 5.  Varieties that get taller than 2 feet may need stakes or other supports. Dahlias may languish during the heat of summer, but keep them mulched and provide plenty of water and they will reward you with a show from late summer through fall to first frost. Deadhead spent flowers to extend blooming.

Dahlias are herbaceous perennials, but typically grown as an annual. The tuberous roots will not survive winter in the ground in most of the Piedmont region and the western part of the state, so those of us in these regions must be prepared to dig roots in the fall to store during the winter. The dahlia is hardy in the Raleigh area and east to the Coast.

When planting, cover tubers to a depth of 3 inches. Note that these plants can be injured at temperatures below 25 degrees F (2 degrees C). When grown from tubers, dahlias tend to be tall and may require staking. Dahlias can also be grown from seed-germinated selections but these are typically dwarfs and often not heat tolerant, lack uniformity of growth, and are poor bloomers.

Insects, Diseases, and Other Plant Problems:  They can be difficult to grow and suffer from many problems including aphids, leafhoppers, and caterpillars.  Potential diseases include powdery mildew, root rot, crown gall, viruses, and wilts.  This plant may cause contact dermatitis in some people.  

 

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#window boxes#cpp#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
 
Cultivars / Varieties:
  • 'Mystic Enchantment'
    Red blooms
  • 'Peaches And Dreams'
'Mystic Enchantment', 'Peaches And Dreams'
Tags:
#showy flowers#poisonous#heat tolerant#houseplant#window boxes#cpp#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
  • Attributes:
    Genus:
    Dahlia
    Family:
    Asteraceae
    Life Cycle:
    Bulb
    Perennial
    Recommended Propagation Strategy:
    Division
    Root Cutting
    Country Or Region Of Origin:
    Mexico, Central America, Tropical America
    Wildlife Value:
    attracts butterflies
    Bulb Storage:
    In Zone 8 harvest tuberous roots in fall, dry carefully (do not wash), and store in vermiculite or dry sand at 35-45 degrees F (2-7 degrees C). In Zone 7, just mulch.
    Edibility:
    Toxic. Were grown as a food crop by Aztecs, but 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
    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:
    Black
    Cream/Tan
    Gold/Yellow
    Orange
    Pink
    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 involucar bracts at the base. Flowering heads are usually large (ranging from 2 to 12 inches), with many petals, variously colored 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 Involucral bracts dimorphic, in two rows; outer row obovate, conspicuously reticulate veined, spreading to reflexed, inner row broad, membraneous, green, appressed to ray flowers. Disc and ray flowers variable in color and are anthocyanin or carotenoid pigmented. Garden origin.
  • Leaves:
    Woody Plant Leaf Characteristics:
    Deciduous
    Leaf Color:
    Black
    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, reddish-purple, or purple-black.
  • Stem:
    Stem Color:
    Brown/Copper
    Red/Burgundy
    Stem Is Aromatic:
    No
  • Landscape:
    Landscape Location:
    Container
    Houseplants
    Landscape Theme:
    Cottage Garden
    Cutting Garden
    Design Feature:
    Accent
    Border
    Mass Planting
    Small groups
    Attracts:
    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:
    Toxic if eaten in large quantities. Skin irritation following repeated handling of the tubers and contact with leaves and light. Mild gastrointestinal signs.
    Poison Toxic Principle:
    Phototoxic polyacetylene compounds
    Causes Contact Dermatitis:
    Yes
    Poison Part:
    Leaves
    Roots