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Swamp Butterfly Weed Asclepias incarnata

Other Common Name(s):

Previously known as:

  • Acerates incarnata
Phonetic Spelling
as-KLEE-pee-as in-kar-NAH-tuh
This plant has low severity poison characteristics.
See below
Description

Swamp milkweed is an herbaceous perennial in the Apocynaceae (dogbane) family. Apocynum is the Greek term for “dog-away.” It is native to the central and eastern United States and tends to grow in wet sites along streams, ponds, or bogs. 

Plant swamp milkweed in full sun to partial shade in soils with neutral to acidic pH. It is native to wet sites but adapts to drier sites in moist clay or loam soils. 

The attractive pink to rose-purple flowers mature in mid-spring and last into early fall. The seed pods split open to release seeds that float on the wind. Milkweed is an important food source for Monarch butterfly caterpillars (Danaus plexippus), and the flowers are visited by many pollinators.  It is resistant to browsing by deer.

Use as an accent or border in a meadow, native, or pollinator garden. It will be at home in a naturalized area or along a pond or stream where it can grow up to 5 feet tall and spread 2 to 3 feet wide.

This plant was selected as the 2005 NC Wildflower of the Year, a program managed by the North Carolina Botanical Garden with some financial support from the Garden Club of North Carolina.

Insects, Diseases, and Other Plant Problems: No significant disease problems. Most common milkweed pests (aphids, milkweed beetles, Monarch larvae, and milkweed tussock moth larvae) are not problematic, but both large and small milkweed bugs can be very damaging to seed pods.

See this plant in the following landscapes:
Vegetable, Herb and Mostly Native Pollinator Garden Native Plant Demonstration Garden All Saints' Episcopal Church
Cultivars / Varieties:
var. pulchra
Tags:
#rain garden#purple flowers#native perennial#nectar plant#low maintenance#rabbit resistant#NC native#deer resistant#Monarch butterfly#border planting#pollinator plant#native wildflower#flowers late spring#flowers midsummer#flowers early summer#flowers late summer#wet soils tolerant#butterfly friendly#flowers early fall#NC Wildflower of the Year#boggy sites#collier preserve tn#accent#hs303
 
Cultivars / Varieties:
var. pulchra
Tags:
#rain garden#purple flowers#native perennial#nectar plant#low maintenance#rabbit resistant#NC native#deer resistant#Monarch butterfly#border planting#pollinator plant#native wildflower#flowers late spring#flowers midsummer#flowers early summer#flowers late summer#wet soils tolerant#butterfly friendly#flowers early fall#NC Wildflower of the Year#boggy sites#collier preserve tn#accent#hs303
  • Attributes:
    Genus:
    Asclepias
    Species:
    incarnata
    Family:
    Apocynaceae
    Life Cycle:
    Perennial
    Country Or Region Of Origin:
    Central & E. Canada to W. Central & E. U.S.A.
    Distribution:
    Northeastern and southeastern United States
    Fire Risk Rating:
    medium flammability
    Wildlife Value:
    This plant provides nectar for pollinators including Monarch (Danaus plexippus) butterflies. It is the larval host plant for Monarch (Danaus plexippus) larvae. Its flowers are attractive to pollinators. Deer tolerant.
    Play Value:
    Wildlife Food Source
    Particularly Resistant To (Insects/Diseases/Other Problems):
    Deer and rabbit resistant
    Dimensions:
    Height: 3 ft. 0 in. - 5 ft. 0 in.
    Width: 2 ft. 0 in. - 3 ft. 0 in.
  • Whole Plant Traits:
    Plant Type:
    Herbaceous Perennial
    Native Plant
    Poisonous
    Wildflower
    Woody Plant Leaf Characteristics:
    Deciduous
    Habit/Form:
    Clumping
    Erect
    Growth Rate:
    Medium
    Maintenance:
    Low
  • 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:
    Clay
    High Organic Matter
    Loam (Silt)
    Soil pH:
    Acid (<6.0)
    Neutral (6.0-8.0)
    Soil Drainage:
    Good Drainage
    Moist
    Occasionally Wet
    Available Space To Plant:
    3 feet-6 feet
    NC Region:
    Coastal
    Mountains
    Piedmont
    USDA Plant Hardiness Zone:
    3a, 3b, 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b
  • Fruit:
    Fruit Color:
    Brown/Copper
    Cream/Tan
    White
    Fruit Value To Gardener:
    Showy
    Display/Harvest Time:
    Fall
    Fruit Type:
    Follicle
    Fruit Length:
    > 3 inches
    Fruit Width:
    1-3 inches
    Fruit Description:
    3-4-inch long follicle seed pods split on one side to release seeds with tufts of hair that float on the wind. They are green and mature to brown.
  • Flowers:
    Flower Color:
    Pink
    White
    Flower Inflorescence:
    Umbel
    Flower Value To Gardener:
    Fragrant
    Showy
    Flower Bloom Time:
    Fall
    Summer
    Flower Shape:
    Crown
    Flower Petals:
    4-5 petals/rays
    Flower Size:
    < 1 inch
    Flower Description:
    Individual flowers are ΒΌ" across, consisting of 5 white upright crowns and 5 surrounding pink to mauve petals that droop downward. Blooms in clusters called umbrels on terminal stems. Flower blooms from July to September.
  • Leaves:
    Woody Plant Leaf Characteristics:
    Deciduous
    Leaf Color:
    Green
    Leaf Feel:
    Smooth
    Leaf Type:
    Simple
    Leaf Arrangement:
    Opposite
    Leaf Shape:
    Lanceolate
    Oblong
    Leaf Margin:
    Entire
    Hairs Present:
    No
    Leaf Length:
    3-6 inches
    Leaf Width:
    < 1 inch
    Leaf Description:
    Lanceolate to oblong-lanceolate green leaves are 3-6 inches long .5 to 1.5 inches wide with pointed apex and entire margins. They are either sessile or clasping.
  • Stem:
    Stem Color:
    Green
    Stem Is Aromatic:
    No
    Stem Surface:
    Polished
    Stem Description:
    Stems exude a toxic milky sap when cut.
  • Landscape:
    Landscape Location:
    Coastal
    Meadow
    Near Septic
    Pond
    Pool/Hardscape
    Riparian
    Slope/Bank
    Landscape Theme:
    Butterfly Garden
    Native Garden
    Pollinator Garden
    Rain Garden
    Design Feature:
    Accent
    Border
    Attracts:
    Butterflies
    Pollinators
    Resistance To Challenges:
    Deer
    Rabbits
    Wet Soil
    Problems:
    Contact Dermatitis
    Poisonous to Humans
    Problem for Cats
    Problem for Dogs
    Problem for Horses
  • Poisonous to Humans:
    Poison Severity:
    Low
    Poison Symptoms:
    Can cause stomach upset, nausea, vomiting, abdominal pain, diarrhea, weakness, lethargy, and confusion if eaten in quantity. Milky sap can cause contact dermatitis and eye irritation
    Poison Toxic Principle:
    Cardiac glycosides and resinoids
    Causes Contact Dermatitis:
    Yes
    Poison Part:
    Flowers
    Fruits
    Leaves
    Roots
    Seeds
    Stems