General Plant Information (Edit)
Plant Habit: Herb/Forb
Life cycle: Perennial
Sun Requirements: Full Sun
Water Preferences: Mesic
Dry Mesic
Minimum cold hardiness: Zone 8a -12.2 °C (10 °F) to -9.4 °C (15 °F)
Maximum recommended zone: Zone 10b
Plant Height: 4-6 feet
Plant Spread: 2-3 feet
Flowers: Showy
Flower Color: White
Bloom Size: Under 1"
Flower Time: Summer
Uses: Suitable as Annual
Wildlife Attractant: Butterflies
Resistances: Deer Resistant
Drought tolerant
Toxicity: Leaves are poisonous
Roots are poisonous

Image
Common names
  • Hairy Balls
  • Giant Swan Milkweed
  • Balloon Plant
  • Milkweed
  • Balloon Cotton Bush
Botanical names
  • Accepted: Gomphocarpus physocarpus
  • Synonym: Asclepias physocarpa
  • Synonym: Gomphocarpus semilunatus

Photo Gallery
Location: Louis Ginter Botanical Garden, Richmond, Virginia
Date: 2021-09-12
Photo by poisondartfrog
Location: Winter Springs, FL zone 9b
Date: 2019-07-06
Location: St Louis - MoBOT
Location: Winter Springs, FL zone 9b
Date: 2019-06-15
Location: At Annie's Annuals Nursery
Date: Sep 14, 2008 11:41 AM

Date: 2018-08-17
Location: Louis Ginter Botanical Garden, Richmond, Virginia
Date: 2021-09-12

Photo courtesy of Annie's Annuals and Perennials

Date: 2016-10-03
a/k/a Hairy Balloon plant  Dogbane Family (Apocynaceae)
Photo by hawkarica
Location: my garden
Location: Jefferson County, Texas
Date: 2016-08-13
Location: My garden in Albuquerque, NM Zone 7b
Date: 07.25.21
"Hairy balls" truly does describe these pods
Location: My garden in Albuquerque, NM Zone 7b
Date: 07.26.21
Oleander aphids aka Milkweed aphids
Location: My Property Sunset Zone 23 Fallbrook California
Date: 2012-06-22
Location: San Diego, CA
Date: 2017-07-16
Location: Northeastern Colorado
Date: 2022-09-09
Location: South-Africa 
Date: 2017-02-04
Photo by hawkarica
Location: My Property Sunset Zone 23 Fallbrook California
Date: 2012-06-22
Location: At Annie's Annuals Nursery
Date: Sep 14, 2008 11:42 AM
Location: Jefferson County, Texas
Date: 2016-08-13
Location: Harry P. Leu Botanical Gardens, Orlando Florida
Date: 2011-05-30
gomphocarpus physocarpus, Balloon Milkweed
Location: Chicago Botanic Garden
Date: 2018-09-01
Location: Botanical Garden of Amsterdam
Date: 2013-08-09
Location: Botanical Garden of Amsterdam
Date: 2013-08-09
Location: Botanical Garden of Amsterdam
Date: 2013-08-09
Location: Drakenbergen - South-Africa
Date: 2016-07-26
Location: National Botanical Garden (DC) | November 2022
Date: 2022-11-26
Location: New York, NY
Date: 2014-10
Bronx bot garden
Location: My Property Sunset Zone 23 Fallbrook California
Date: 2012-06-22
Location: My Property Sunset Zone 23 Fallbrook, California
Date: 2012-06-22
Location: My property Sunset Zone 23 Fallbrook California
Date: 2012-06-22
Location:  
Date: 2010-09-24
Location: Chicago Botanic Garden
Date: 2018-09-01
Location: Chicago Botanic Garden
Date: 2018-09-01
Location: My garden in Albuquerque, NM Zone 7b
Date: 07.12.21
Flowers on floppy stems

Photo courtesy of Annie's Annuals and Perennials

Photo courtesy of Annie's Annuals and Perennials

Photo courtesy of Annie's Annuals and Perennials
  • Uploaded by Joy
Location: South-Africa
Date: 2017-02-04
Cut open
Location: Downingtown, Pennsylvania
Date: 2021-09-08
one plant in a yard
Photo by hawkarica
Location: Hawaii
credit: Forest & Kim Starr
Location: My garden in N E Pa. 
Date: 2021-10-19
Location: South-Africa 
Date: 2017-02-04
In its native habitat
Location: Downingtown, Pennsylvania
Date: 2021-09-08
bumblebee on white flowers
Photo by hawkarica
Comments:
  • Posted by NMoasis (Albuquerque NM, Elev 5310 ft - Zone 7b) on Aug 26, 2021 10:14 PM concerning plant:
    I really wanted to love my Gomphocarpus physocarpus* aka balloon plant, balloon cotton-bush, bishop's balls, monkey balls, hairy balls, nailhead and swan plant. I obtained an 8" plant and it grew incredibly fast and floppy as reported and soon needed the tomato cage I had installed. The flowers were plentiful and fascinating and pods developed quickly. When it was about five feet tall the Aphis nerii Boyer de Fonscolombe arrived—a fancy name for Milkweed aphids—in massive numbers. If I had a bigger garden and could grow this plant somewhere off in a corner, I would have ignored them, but I had parked it between herbs and tomatoes and even though the aphids clearly preferred the milkweed, they did travel to surrounding plants. Their honeydew coated everything nearby. Then the ants arrived. With heavy heart I cut it down, sealed it in a plastic bag and put it in the trash because it was too infested with aphids to compost.

    *Its name changed from Asclepias physocarpa in 2001 to reflect that it is in the family of African milkweeds.
  • Posted by ILPARW (southeast Pennsylvania - Zone 6b) on Sep 9, 2021 7:11 PM concerning plant:
    This member of the Milkweed Family is from southern Africa. It is used as an annual flower in the northern US. I came upon this new species to me in a neighbor's yard this September 2021. The neighbor said she was given the plant from a friend who ordered some online from a company that sells plants good for butterflies. I've never seen it in a garden center yet. I'm sure my friends in the American Native Plant Movement would have doubts about this Balloon-Plant or Hairy Balls really being good for the Monarch Butterfly, as they oppose the use of the Annual Milkweed from South America as not really being good for Monarchs. I have not seen any literature so far saying that there is a down side.
  • Posted by fosnightr on Aug 21, 2023 1:24 PM concerning plant:
    My plant isn't blooming. I planted it this spring. It's between 4 and 5 feet high, full sun. Central Ks
Plant Events from our members
antsinmypants On April 29, 2023 Seeds germinated
Water method experiment. 1 seedling has germinated. Transplanted into soil.
antsinmypants On April 29, 2023 Plant emerged
1 seedling has emerged.
antsinmypants On April 21, 2023 Seeds sown
Water method experiment. 4 seeds.
antsinmypants On April 7, 2023 Seeds sown
3 sown after a 24-hour soak.
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