Asclepias Species, Swamp Milkweed, Rose Milkweed, Swamp Silkweed
Asclepias incarnata
Family: | Apocynaceae (a-pos-ih-NAY-see-ee) (Info) |
Genus: | Asclepias (ass-KLE-pee-us) (Info) |
Species: | incarnata (in-kar-NAH-tuh) (Info) |
Synonym: | Asclepias incarnata subsp. incarnata |

Category:
Perennials
Water Requirements:
Requires consistently moist soil; do not let dry out between waterings
Sun Exposure:
Sun to Partial Shade
Foliage:
Herbaceous
Foliage Color:
Height:
24-36 in. (60-90 cm)
36-48 in. (90-120 cm)
4-6 ft. (1.2-1.8 m)
Spacing:
24-36 in. (60-90 cm)
Hardiness:
USDA Zone 3a: to -39.9 °C (-40 °F)
USDA Zone 3b: to -37.2 °C (-35 °F)
USDA Zone 4a: to -34.4 °C (-30 °F)
USDA Zone 4b: to -31.6 °C (-25 °F)
USDA Zone 5a: to -28.8 °C (-20 °F)
USDA Zone 5b: to -26.1 °C (-15 °F)
USDA Zone 6a: to -23.3 °C (-10 °F)
USDA Zone 6b: to -20.5 °C (-5 °F)
USDA Zone 7a: to -17.7 °C (0 °F)
USDA Zone 7b: to -14.9 °C (5 °F)
USDA Zone 8a: to -12.2 °C (10 °F)
USDA Zone 8b: to -9.4 °C (15 °F)
Where to Grow:
Grow outdoors year-round in hardiness zone
Danger:
All parts of plant are poisonous if ingested
Bloom Color:
Pink
Medium Purple
Bloom Characteristics:
This plant is attractive to bees, butterflies and/or birds
Bloom Size:
Bloom Time:
Mid Summer
Late Summer/Early Fall
Other details:
Soil pH requirements:
5.6 to 6.0 (acidic)
6.1 to 6.5 (mildly acidic)
6.6 to 7.5 (neutral)
Patent Information:
Non-patented
Propagation Methods:
By dividing rhizomes, tubers, corms or bulbs (including offsets)
From seed; direct sow outdoors in fall
From seed; winter sow in vented containers, coldframe or unheated greenhouse
From seed; stratify if sowing indoors
Seed Collecting:
Bag seedheads to capture ripening seed
Allow pods to dry on plant; break open to collect seeds
Properly cleaned, seed can be successfully stored
Regional
This plant is said to grow outdoors in the following regions:
Elmore, Alabama
Mabelvale, Arkansas
North Little Rock, Arkansas
Sacramento, California
Kiowa, Colorado
Littleton, Colorado
Dover, Delaware
Fort Lauderdale, Florida
Gibsonton, Florida
Loxahatchee, Florida
Lutz, Florida
Saint Cloud, Florida
Sarasota, Florida
Bogart, Georgia
Demorest, Georgia
Marietta, Georgia
Anna, Illinois
Cherry Valley, Illinois
Crest Hill, Illinois
Crystal Lake, Illinois
Divernon, Illinois
Edwardsville, Illinois
Evanston, Illinois
Itasca, Illinois
La Grange Park, Illinois
Machesney Park, Illinois
Mount Prospect, Illinois
Springfield, Illinois
Thomasboro, Illinois
Greenville, Indiana
Indianapolis, Indiana
Washington, Indiana
Ames, Iowa
Iowa City, Iowa
Yale, Iowa
Brookville, Kansas
Derby, Kansas
Hiawatha, Kansas
Barbourville, Kentucky
Prospect, Kentucky
New Orleans, Louisiana
Slidell, Louisiana
Brookeville, Maryland
Dundalk, Maryland
Riverdale, Maryland
Springfield, Massachusetts
Allen Park, Michigan
Barton City, Michigan
Dearborn Heights, Michigan
East Tawas, Michigan
Grand Rapids, Michigan
Kasota, Minnesota
Minneapolis, Minnesota(2 reports)
Onamia, Minnesota
Pequot Lakes, Minnesota
Saint Paul, Minnesota
Young America, Minnesota
Kansas City, Missouri
Saint Louis, Missouri
Helena, Montana
Beatrice, Nebraska
Lincoln, Nebraska
Frenchtown, New Jersey
Jersey City, New Jersey
Morristown, New Jersey
Mount Laurel, New Jersey
Westwood, New Jersey
Elephant Butte, New Mexico
Blossvale, New York
Brooklyn, New York
Manorville, New York
Ogdensburg, New York
Charlotte, North Carolina
Hays, North Carolina
Tobaccoville, North Carolina
Fargo, North Dakota
Bowling Green, Ohio
Columbus, Ohio(2 reports)
Dayton, Ohio(2 reports)
Fairborn, Ohio
Findlay, Ohio
Fort Jennings, Ohio
Glouster, Ohio
Napoleon, Ohio
Oak Harbor, Ohio
Saint Marys, Ohio
Springboro, Ohio
Portland, Oregon
Malvern, Pennsylvania
Milford, Pennsylvania
Norristown, Pennsylvania
Philadelphia, Pennsylvania
Waynesboro, Pennsylvania
West Chester, Pennsylvania
Wilkes Barre, Pennsylvania
Conway, South Carolina
Okatie, South Carolina
Rock Hill, South Carolina
Parker, South Dakota
Viola, Tennessee
Belton, Texas
Fort Worth, Texas
Los Fresnos, Texas
Salt Lake City, Utah
Arlington, Virginia
Leesburg, Virginia
Manassas, Virginia
Mc Lean, Virginia
Newport News, Virginia
Portsmouth, Virginia
Sterling, Virginia
Orchards, Washington
Spokane, Washington
Berkeley Springs, West Virginia
Cabin Creek, West Virginia
Liberty, West Virginia
De Pere, Wisconsin
Madison, Wisconsin
Milwaukee, Wisconsin
show allGardeners' Notes:
Rating | Content |
---|---|
Positive | On Sep 22, 2016, FlyPoison from Rock Hill, SC (Zone 7a) wrote: Grows very well in clay, preferably a low area and plenty of sun, in these parts. It took 2-3 years to get well established and is now very drought tolerant. Mine adds 1-2 new offshoots each year. |
Positive | On Jul 14, 2015, vitz wrote: direct sown outside in mid/late may in pueblo west, co. . 1st germinators are now about 1.5' tall, w/ 'branches', and 'wooden' main stem bases. during the first few weeks, every single seedling (about a dozen, in an outside 'bed' of coconut coir and potting soil) got munched by something down to the last leaf. they all then spurted like mad and now seem to be left completely alone by any bug/pest. mine get full sun from dawn to about 3 p.m., light watering 2x/daily. looking forward to seeing the blooms. wondering if the plant produces something after the initial growth that repels bugs, etc.. seems easy to grow. |
Positive | On Feb 8, 2014, Rickwebb from Downingtown, PA wrote: I've seen it in two moist meadows at land preserves in southeast Pennsylvania that have been restored to being of native flora. I've also seen it planted in a few gardens where it makes a great upright perennial that is sometimes sold at a good number of garden centers. There is a white blooming form I've seen in a garden. |
Positive | On Jun 15, 2013, Chillybean from (Zone 5a) wrote: We bought some plugs last spring, along with a couple of other natives. They were decimated by Oleander Aphids last year, but have bounced back quite nicely this spring. Even with last year's drought. The other natives did not fair quite so well; there's no sign of them. |
Positive | On Sep 5, 2011, patti525 from Westwood, NJ wrote: We just added some of these to our sunny garden in Westwood, NJ, (bought them on eBay in July because I couldn't find a local nursery that sells them) and it's Labor Day weekend, and we already have a Monarch caterpillar; this seems late in the season to me, but we certainly are enjoying our good luck! Also have some beautiful pink blooms. |
Positive | On Sep 5, 2011, mom4monarchs from Dover, DE wrote: I have found swamp milkweed to be the easiest to grow of the milkweed varieties I've tried. The monarchs love it (and they desperately need our help). The only problem is that by August the leaves turn yellow and then drop on some plants. (Any advice would be appreciated). One tip for propagation is to cut off a stem, remove the leaves, cut it into 6 inch pieces and and put the pieces into pots. New leaves will appear within a few weeks - much faster than seeds. |
Positive | On Feb 21, 2011, pirateradio from Waynesboro, PA wrote: Swamp milkweed is native to my property. Last year, I collected seeds & this year, I've started seedlings inside to bolster the yard against some of the nasty invasives (Canada thistle, exotic honeysuckles, etc.) that also are growing here. |
Positive | On Apr 27, 2010, abbyschult from Saint Louis, MO wrote: Question. I planted this last year and it did well. I am waiting for it to come up again and so far, nothing. it's 4/28/10. shouldn't something be appearing in the grass? |
Positive | On Nov 4, 2009, tcs1366 from Leesburg, FL (Zone 9b) wrote: Surprisingly -- these have grown for me in dry conditions. They are in a flower bed that I do not water, only when it rains -- and they seem to do just fine. |
Positive | On Oct 14, 2009, Q734 from Allen Park, MI wrote: This plant returns every year. I clip pods while green to control spread or use the sprouts to rear monarchs in pots. It gets about 3 feet high and at least as wide. |
Positive | On Aug 14, 2009, SusanLouise from Lincoln, NE (Zone 5b) wrote: Our milkweed reached a height of over 5'. One of the 2 pics I submitted shows it's height and width of just 2 plants that are just 2 years old...incredable!!! |
Positive | On Jul 28, 2009, kittysue from Fairborn, OH wrote: I seeded these in my heavy clay soil. They wilt easily when not regularly watered. I water these daily now, unless there is a downpour, I even water when it rains. They bloom all year long. |
Positive | On Jul 8, 2008, grik from Saint Paul, MN wrote: A beautiful milkweed with an intoxicating vanilla scent. Don't let the name fool you. It may in fact like growing in swamps for all I know, but it is very drought tolerant in my garden. |
Positive | On Nov 30, 2006, frostweed from Josephine, Arlington, TX (Zone 8a) wrote: Swamp Milkweed Asclepias incarnata is native to Texas and other States. |
Positive | On Jan 17, 2006, Breezymeadow from Culpeper, VA (Zone 7a) wrote: This plant is native to at least the Piedmont area of Virginia, & I am lucky to have a couple of clumps growing wild in a couple of semi-shady spots on my property. Since they are growing in areas that do get mowed at least once a year, when my perennial gardens are finally established, I will probably relocate these lovely clumps to safety. |
Neutral | On Jan 16, 2006, Gabrielle from (Zone 5a) wrote: Swamp Milkweed blooms are very pretty, but it is extremely susceptible to aphids. I plant mine in the back of my yard where it is there for butterflies, but the aphid-attacked plants won't be in full view. |
Positive | On Feb 22, 2005, CaptMicha from Brookeville, MD (Zone 7a) wrote: Swamp milkweed is a great addition to any butterfly garden. |
Positive | On Feb 11, 2005, ACHunter47 from Elmore, AL (Zone 8a) wrote: I have grown Milkweed for two years. The Monarch caterpillars eat all of the leaves off of the plant. So, don't kill the caterpillars. My plants came back last year and bloomed again after the leaves were eaten. I had a couple of the caterpillars build their chrysalis on the side of my greenhouse. I took pictures of them at certain stages. It was very interesting and exciting to watch them develop into butterflys and fly away. |
Positive | On Oct 23, 2004, SalmonMe from Springboro, OH (Zone 6a) wrote: Worthy to note that not only do Monarchs LIKE Asclepias, but Asclepias plants are the ONLY kind of plant that the larvae/caterpillars can survive on. The caterpillars do not eat any other host plant. It helps, too, that the plants are truly lovely. |
Positive | On Aug 31, 2003, suncatcheracres from Old Town, FL wrote: I'm always happy to find a new plant for Monarchs, which are threatened in the wild. This entry gave me the interest to look this plant up in some books, and I found out it really likes wet conditions, which I have in Northcentral Florida, zone 8b, so I'll look for some seed to start plants next Spring. I'm at the bottom end of its range, but I'll try hard to find the right niche for it. |
Positive | On Jan 16, 2003, MossRose from Albany, MO (Zone 5a) wrote: Bloomed the first year from seed, started early in greenhouse. Thrived in drought conditions. |
Neutral | On Aug 12, 2001, poppysue from Westbrook, ME (Zone 5a) wrote: This member of the milkweed family is a well-behaved garden plant. It forms a large clump and will not spread by runners like so many of its cousins. The flowers clusters are 2-4 inches across and have a nice fragrance. It prefers full sun and loves wet soils but it will also grow well in average garden soil. |