Asclepias Species, Butterfly Milkweed, Butterflyweed for Clay

Asclepias tuberosa var. clay

Family: Apocynaceae (a-pos-ih-NAY-see-ee) (Info)
Genus: Asclepias (ass-KLE-pee-us) (Info)
Species: tuberosa var. clay
View this plant in a garden



Foliage Color:

Unknown - Tell us

Bloom Characteristics:

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

Water Requirements:

Drought-tolerant; suitable for xeriscaping

Where to Grow:

Unknown - Tell us


24-36 in. (60-90 cm)


15-18 in. (38-45 cm)


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)

USDA Zone 10a: to -1.1 C (30 F)

USDA Zone 10b: to 1.7 C (35 F)

Sun Exposure:

Full Sun


Parts of plant are poisonous if ingested

Bloom Color:


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

Self-sows freely; deadhead if you do not want volunteer seedlings next season

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 has been said to grow in the following regions:

Chaska, Minnesota

Buffalo, New York

Hampstead, North Carolina

Holly Springs, North Carolina

Spencer, West Virginia

Gardeners' Notes:


On Feb 12, 2012, treesmoocher from Spencer, WV wrote:

I have not bought this plant; it was already growing on my site. But there's no doubt it's growing in heavy clay, and that it's happy, healthy and beautiful. I now have several of these in my vegetable garden, because I never eradicated them and the roots apparently survive below tilling depth. Also successfuly transplanted one into my flowerbed last year. So I can't say how it might compare to a non clay tolerant version. But I have saved seeds, which I could mail someone.


On Jun 6, 2009, mcrousse from Holly Springs, NC (Zone 7b) wrote:

So far so good - this is the second year I've had this plant. I have it on a clay slope in one of the hottest driest spots in my yard. It has had no trouble at all with our heat and humidity and erratic winter weather. It has not yet bloomed as I think it needs to grow a bit first from the size you receive from the nursery. It has more stalks this year so I am thinking it might bloom later.

Edit: July 2010 this plant finally bloomed, 3 years after it was planted. It looks just like a regular asclepias tuberosa bloom and survived just fine with 3 days over 100 degrees and high humidity.