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
View this plant in a garden



Water Requirements:

Requires consistently moist soil; do not let dry out between waterings

Sun Exposure:

Sun to Partial Shade



Foliage Color:

Unknown - Tell us


24-36 in. (60-90 cm)

36-48 in. (90-120 cm)

4-6 ft. (1.2-1.8 m)


24-36 in. (60-90 cm)


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


All parts of plant are poisonous if ingested

Bloom Color:


Medium Purple

Bloom Characteristics:

This plant is attractive to bees, butterflies and/or birds

Bloom Size:

Unknown - Tell us

Bloom Time:

Mid Summer

Late Summer/Early Fall

Other details:

Unknown - Tell us

Soil pH requirements:

5.6 to 6.0 (acidic)

6.1 to 6.5 (mildly acidic)

6.6 to 7.5 (neutral)

Patent Information:


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


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 all

Gardeners' Notes:


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.


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.


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.


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.


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.


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.


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.


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?


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.


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.


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!!!
Since I don't need anymore milkweed of this variety, I do harvest all the pods before they open since I don't want them to multiply in our garden/yard. This is one plant, due to it's size, that I don't want it to self sow...even accidentally!


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.


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.


On Nov 30, 2006, frostweed from Josephine, Arlington, TX (Zone 8a) wrote:

Swamp Milkweed Asclepias incarnata is native to Texas and other States.


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.

The pink flower clusters are pretty, with a subtle sweet fragrance. As others have stated, they're very attractive to butterflies.


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.

I have read that it is hardy in zones 3-9.

Blooms June-August in my garden.


On Feb 22, 2005, CaptMicha from Brookeville, MD (Zone 7a) wrote:

Swamp milkweed is a great addition to any butterfly garden.

It's well behaved and grows in a wide range of climates, despite it's name. Although, it probably grows better given care like that of it's natural conditions.

Swamp milkweed is prone to aphid infestations, though not so bad. It's also prone to milkweed bug, such as the beetle, infestations but not as much as the thicker stemmed milkweeds.

Butterflies flock to this particular milkweed because it's tall, attractively colored and the foliage is suffiently tender for larvae.


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.


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.


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.

The pretty pink color should go nicely with my pink Brugmansias, and pink azaleas, and pink cannas and pink tiger lilies. Obviously I'm developing a pink bed, with a little cream and paler yellows thrown in for variety. This bed has a mixture of sun and shade, so I'll find a place for this pretty and useful plant. I read it grows three to five feet tall, so it would make a nice backgr... read more


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.


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.

It's a wonderful addition to a butterfly garden. The adults sip nector from the flowers and monarch butterflies use it as a host plant. The female will lay her eggs on the plant and the young caterpillars feed on the foliage.