Asclepias Species, Showy Milkweed, Showy Butterfly Weed, Creek Milkweed, Greek Milkweed

Asclepias speciosa

Family: Apocynaceae (a-pos-ih-NAY-see-ee) (Info)
Genus: Asclepias (ass-KLE-pee-us) (Info)
Species: speciosa (spee-see-OH-suh) (Info)
Synonym:Asclepias douglasii
Synonym:Asclepias giffordii



Water Requirements:

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

Sun Exposure:

Full Sun




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)

USDA Zone 9a: to -6.6 C (20 F)

USDA Zone 9b: to -3.8 C (25 F)

Where to Grow:

Grow outdoors year-round in hardiness zone


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:

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:

Flagstaff, Arizona

Sun City, Arizona

Brentwood, California

Calistoga, California

Janesville, California

Laguna Beach, California

Long Beach, California

Richmond, California

San Jose, California

San Leandro, California

San Marcos, California

Susanville, California

Westminster, California

Colorado Springs, Colorado

Golden, Colorado

Laporte, Colorado

Paonia, Colorado

Bokeelia, Florida

Potlatch, Idaho

Rock Rapids, Iowa

Barbourville, Kentucky

Eveleth, Minnesota

Minneapolis, Minnesota

Helena, Montana

Oklahoma City, Oklahoma

Cottage Grove, Oregon

Portland, Oregon

Wilkes Barre, Pennsylvania

Austin, Texas

Magna, Utah

Salt Lake City, Utah

South Jordan, Utah

Bonney Lake, Washington

Orchards, Washington

Prairie Ridge, Washington

show all

Gardeners' Notes:


On Aug 4, 2018, Chambo from Sumner, WA wrote:

Seeds were planted mid-June 2017, but did not flower the first year. In 2018, 5 plants came up with the tallest at 54"; one is now with a large seed pod (1st wk of August). The soil here in Bonney Lake is typical of the northwest: acidic.


On Aug 22, 2017, Salernitana9 from San Jose, CA wrote:

I am in zone 9b (South San Jose, CA) with extremely heavy clumpy clay soil. I was unsuccessful in planting over thirty milkweed seeds that I purchased online from two different ebay vendors and failed even in methods obtained from never-fail-youtube videos. I lucked out and randomly found in the late Summer a milkweed plant over at the Westbrae Nursery in Berkeley so that I didn't need to order one online from Annie's in Richmond.
The plant did fine and grew a few inches with no flowers, but I needed to transplant it after a couple of months due to renovations. The plant also did fine in the new location and grew an inch after a few weeks. Out of the blue, five baby milkweed plants sprouted up in the original place from where the plant had been transplanted. I unsuccessf... read more


On Mar 26, 2016, coriaceous from ROSLINDALE, MA wrote:

Not as a attractive as butterfly weed (A. tuberosa) or swamp milkweed (A. incarnata), which are also excellent food sources for Monarch butterfly caterpillars (and great nectar sources for adults), and are easy garden plants that form clumps.

Despite the name, A. speciosa is a dowdy plant that looks a lot like common milkweed (A. syriaca), but it though it doesn't spread as quickly it can still spread aggressively underground under some conditions.


On Dec 28, 2008, aardvark7 from Lubbock, TX (Zone 7b) wrote:

Free seeds for Asclepias speciosa may be obtained through on their website. Milkweed is the ONLY larval food source for the Monarch butterfly.


On Jul 29, 2008, Danny112596 from Los Fresnos, TX (Zone 10a) wrote:

This plant may grow in Zone 10 with good care. To grow them in Zone 10 from seeds use Cold Moist Stratification for a 1-2 months then plant.


On Oct 22, 2005, wetdogfarm from Eveleth, MN (Zone 3a) wrote:

I have been growing this species for several years in N MN. It has done fine in average garden soil and tolerates some drought. It does not seem to need consistent moisture in my opinion. It spreads by rhizomes, but not as rampantly as Asclepias syriaca. Beautiful flowers.


On Dec 4, 2004, smiln32 from Oklahoma City, OK (Zone 7a) wrote:

This plant attracts bees and butterflies. The flowers are pinkish-whitish and reach a height of 28". They look like a cluster of little stars.

It is native to the U.S. and are found in fields, along roadsides and in prairie meadows. The tan, three inch long seed pod contains fuzz around the seeds. It was used in the past as pillow stuffing.