Showy Milkweed (Speciosa)

The Showy Milkweed (Speciosa) is generally described as a perennial forb/herb. This is native to the U.S. (United States) has its most active growth period in the spring and summer . The Showy Milkweed (Speciosa) has green foliage and inconspicuous white flowers, with an abuncance of conspicuous black fruits or seeds. The greatest bloom is usually observed in the early summer, with fruit and seed production starting in the summer and continuing until summer. Leaves are not retained year to year. The Showy Milkweed (Speciosa) has a long life span relative to most other plant species and a moderate growth rate. At maturity, the typical Showy Milkweed (Speciosa) will reach up to 6 feet high, with a maximum height at 20 years of 0 inches.

The Showy Milkweed (Speciosa) is easily found in nurseries, garden stores and other plant dealers and distributors. It can be propagated by container, seed. It has a moderate ability to spread through seed production and the seedlings have medium vigor. Note that cold stratification is not required for seed germination and the plant cannot survive exposure to temperatures below -33°F. has low tolerance to drought and restricted water conditions.

Uses of : Landscaping, Medicinal, Culinary, etc.

Warning: Milkweed may be toxic when taken internally, without sufficient preparation.

Ethnobotanic: People have used milkweed for fiber, food, and medicine all over the United States and southern Canada. Fibers from the stems of milkweed have been identified in prehistoric textiles in the Pueblo region. Tewa-speaking people of the Rio Grande still make string and rope from these fibers. At Zuni, the silky seed fibers are spun on a hand-held wooden spindle and made into yarn and woven into fabric, especially for dancers. Pueblo people ate green milkweed pods and uncooked roots from one of the species that forms fleshy tubers underground.

Milkweeds (especially Asclepias speciosa) supply tough fibers for making cords and ropes, and for weaving a coarse cloth. Milkweed stems were collected after the stalks dried in late fall early winter. The dried stalks were split open to release the fibers; milkweed fibers were sometimes mixed with fibers of Indian-hemp (Apocynum cannabinum). The bark is removed and the fibers released by first rubbing between the hands and then drawing the fibers over a hard surface. Twisting the fiber opposite each other and twining them together formed the cord; often this was accomplished by rolling the fibers on the thigh while twisting them together.

Vast quantities of fiber plants are required for the making of nets, regalia, and cordage by California Indians. Blackburn and Anderson (1993) quote Craig Bates of the Yosemite Museum that it takes approximately five stalks of milkweed or Indian hemp to manufacture one foot of cordage. A Sierra Miwok feather skirt or cape contain about 100 feet of cordage made from approximately 500 plant stalks, while a deer net 40 feet in length contained some 7,000 feet of cordage, which would have required the harvesting of a staggering 35,000 plant stalks, (Barrett and Gifford 1933:178).

The young shoots, stems, flower buds, immature fruits, and roots of showy milkweed were boiled and eaten as a vegetable by various indigenous groups of eastern and mid-western America.

In some areas the young leaves and stems were used as greens. The flowers were also eaten raw or boiled, and the buds were boiled for soup or with meat. The most common use for these plants, recorded among almost all the tribes throughout California, was to obtain a kind of chewing gum from the sap of Asclepias speciosa. The sticky white sap was heated slightly until it became solid, then added to salmon fat or deer grease.

The sap of Asclepias speciosa was used as a cleansing and healing agent by some of the desert tribes for sores, cuts, and as a cure for warts and ringworm. The silky hairs were burned off the ripe seeds, which were then ground and made into a salve for sores. Seeds were boiled in a small amount of water and the liquid used to soak rattlesnake bites to draw out the poison. A hot tea made from the roots was given to bring out the rash in measles or as a cure for coughs. It was also employed as a wash to cure rheumatism. The mashed root, moistened with water, was used as a poultice to reduce swellings.

Insectary: Milkweed species are attractive to butterflies, bees, and other insects. Accordingly, this is a wonderful horticultural plant for beautiful floral landscaping that attracts butterflies (particularly Monarchs) and other insects.

Monarch butterflies are specific to milkweed plants. This is the only type of plant on which the eggs are laid and the larvae will feed and mature into a chrysalis. Eggs are laid on the underside of young healthy leaves. It is important to have large clumps of milkweeds for the young caterpillars; their response to predation is to drop to the ground and play possum. They cannot find their way back to the milkweed stems, which they need to survive, unless they are fairly densely spaced.

Monarch, Queen and Viceroy butterflies are Müllerian mimics; all are toxic, and have co-evolved similar warning patterns to avoid

General Characteristics

General: Milkweed Family (Asclepiadaceae). Asclepias flowers look like crowns, with the corolla reflexed and hoods elevated above the corolla. Showy milkweed (Asclepias speciosa) is a hairy perennial with stems ascending to erect. The leaves are opposite, persistent, with short petioles, elliptic to ovate blades, and bases rarely cordate and clasping. The corolla is reflexed and rose-purple; the hoods are elevated above the corolla in pink, aging yellow. Horns are exerted beyond the hoods.

Required Growing Conditions

For current distribution, please consult the Plant Profile page for this species on the PLANTS Web site. Milkweed grows in clumps beside roadways and on abandoned farmlands and other open areas, reaching heights of 120 to 150 cm (4 to 5 ft) during the summer. Milkweed species grow throughout the United States. Showy milkweed occurs in many sunny, dry habitats including fields and roadsides, from 0 to 1900 m. The plant occurs in California to British Colombia and Central Canada south to Texas.

Cultivation and Care

Collect seeds after pods have ripened, but before they have split open. The seeds are wind dispersed, so be careful when gathering to place in a paper or burlap bag to avoid seed lost. Seeds can be directly sewn into the ground in the fall. The seed is very viable. Planting seed the first fall after collecting seeds maximizes revegetation success. It is not certain how long seeds can be stored.

Cold treatment for three months improves seed germination in some milkweed species from higher elevations or colder climates (where it freezes in the winter). Revegetation success with milkweeds seems to be improved by planting seeds directly in the ground. High mortality seems to occur with plants in pots and they don't overwinter well in pots. Milkweed plants naturally die back in winter, but re-emerge during the following spring unless planted in a pot

Whole Plant Collections: For milkweed species with rhizomes, propagation by cuttings of the tuberous rhizome is also easy and reliable. The cuttings should be made when the plant is dormant. Each piece of the rhizome should have at least one bud (they are about two inches apart). Timing of propagation is important. Harvest or divide plants and move them in October at the beginning of the rainy season. Place the plants in the ground by late fall so they can develop enough root growth to survive the winter. Irrigation the first year will improve survival, and by the second year the root system should be well enough established so plants will survive on their own. Both seedlings and cuttings will usually bloom in their second year, although cuttings will occasionally bloom during their first year (Kindscher 1992).

General Upkeep and Control

When used for fiber milkweed is collected in the autumn after the leaves have begun to senesce or dry up. Plants grow in places that have been disturbed such as road grading, construction sites, logging landing fills, and etc. Pete Bunting (pers. comm. 2-9-1999) says, In the fall when the milkweed has dried I check to see if they will break off at the ground line. The plants are usually a yellow tan to gray depending on how long they have dried. I like the gray for softer string, but the fibers are shorter. The tan stalks have longer fibers but are also stiff and hard to work but very long. I break off as many of the plants as I can gather as they are going to resprout in the spring. I try and let them dry some more. Then I process them. I have used plants that have over-wintered under snow and they were fine but had soft, short fiber. After 2 winters they are usually no good but you have another year's stalks to pick by then. The dried stalks are then split open and the fibers are twisted into string.

Both milkweed and dogbane were burned in the fall by California Indian tribes to eliminate dead stalks and stimulate new growth. Burning causes new growth to have taller, straighter stems with longer fibers. It also stimulates flower and seed production.

Plant Basics
Growth Rate Moderate
General Type Forb/herb
Growth Period Spring, Summer
Growth Duration Perennial
Lifespan Long
Plant Nativity Native to U.S.
Commercial Availability Routinely Available
Physical Characteristics
Bloom Period Early Summer
Displays Fall Colors No
Shape/Growth Form Single Crown
Drought Tolerance Low
Shade Tolerance Intolerant
Height When Mature 6
Vegetative Spread None
Flower Color White
Flower Conspicuousness Yes
Fruit/Seed Abundance High
Fruit/Seed Seasonality Summer Summer
Seed Spread Rate Moderate
Gardening Characteristics
Propagations (Ways to Grow) Container, Seed
Moisture Requirements Medium
Cold Stratification Required No
Minimum Temperature -33
Soil Depth for Roots 18
Toxic to Nearby Plants No
Toxic to Livestock No
After-Harvest Regrowth Rate Slow
After-Harvest Resprout Ability No
Responds to Coppicing No
Growth Requirements
pH Range 5–7 pH
Precipitation Range 16–16 inches/yr
Planting Density 1200–2700 indiv./acre
Soil Textures Coarse, Fine, Medium
Soil Depth for Roots 18
Minimum Frost-Free Days 90 day(s)
Salinity Tolerance None
CaCO3 Tolerance Medium
Sustainability & Use
Leaf Retention No
Fire Resistant No
Causes Livestock Bloating None

Source: USDA, NRCS, PLANTS Database,
National Plant Data Center, Baton Rouge, LA 70874-4490 USA