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Showy Milkweed
Asclepias speciosa
  


About Showy Milkweed (Asclepias speciosa) Showy milkweed is native to much of the western half of North America. In California it is found in the Sierras and Coast Ranges, from Tulare County to Modoc and Siskiyou Counties. This flowering plant is a hairy, erect perennial that grows to about 4 feet tall. The large, pointed, banana-like leaves are arranged opposite on the stalk-like stem. The fragrant eye-catching furry pale pink to pinkish-purple flowers are arranged in thick umbels. Their petal structure is reflexed and the central flower parts, five hoods with prominent hooks, are star-shaped. The fruit is a large, rough follicle filled with many flat oval seeds with luxuriant silky plumes. It spreads by underground rhizomes, forming an expanding clump. Many Native American peoples utilized all parts of this plant for a great number of medicinal uses and ate some parts as a food. Showy Milkweed is popular with birds and insects, notably the Monarch butterfly. Alkaloids inside the plant are picked up by the caterpillars and give them protection by making them taste awful to predators.
Plant Description
Plant Type
Perennial herb

Max. Height
4 - 6 ft (1.2 - 1.8 m)

Max. Width
4 ft (1.2 m)

Form
Upright, Spreading, Upright Columnar

Fragrance
Fragrant - Pleasant

Growth Rate
Moderate

Dormancy
Winter Deciduous

Flower Color
White, Pink, Purple

Flowering Season
Summer
Spring
Summer
Fall
Winter


Native Status
Native

Natural Setting
Site Type
Flats, meadows, seasonally moist soils, typically in mountainous areas, although it is also found in the central valley

Sun
Sun

Elevation ?
17' - 7825'

Annual Precip. ?
4.9" - 99.5"

Summer Precip. ?
0.22" - 2.81"

Coldest Month ?
26.6° F - 50.5° F

Hottest Month ?
49.6° F - 76.3° F

Humidity ?
0.35 vpd - 30.15 vpd

Soil Description
Tolerates clay soil but performs best with good drainage

Soil PH
6.0 - 8.5

Drainage
Fast, Medium

Cold Tolerance(° F)
Tolerates cold to -5° F

Sunset Zones ?
1, 2*, 3*, 4, 5, 6*, 7*, 8*, 9*, 10*, 14*, 15*, 16, 17, 18*, 19, 20, 21, 22, 23, 24

Wildlife Attracted
Butterflies, especially Monarchs, are attracted to all milkweeds. Many other insects are also attracted.

Landscaping Information
Ease of Care
Very Easy

Water Requirement ?
Low
Extremely Low
Very Low
Low
Moderate - High


Popularity
Very Popular

Max. Summer Water ?
2x/month
No Summer Water
1x/month
2x/month
3x/month
1/week
Keep moist


Mulch
Organic with Rocks

Pruning
If a clump becomes too large, excess rootstock can be pruned during the winter when the plant is dormant

Propagation ?
from seed there are two options A. Place the seeds on a bowl with lid in some water or a damp paper towel and place in the fridge for a few weeks or until sprouted. When sprouted place the sprouts flat on their sides into some damp soil. Cover with a very thin layer of soil. These plants should be planted directly into the ground. They don't transplant well due to long roots (rhizomes) B. Throw seeds onto desired area during the cold months of the year and allow the rain to water them Plant in full sun

Common uses
Butterfly Gardens, Deer Resistant, Bird Gardens

Nursery Availability
Commonly Available



Sources include: Wikipedia. All text shown in the "About" section of these pages is available under the Creative Commons Attribution-ShareAlike License. Plant observation data provided by the participants of the California Consortia of Herbaria, Sunset information provided by Jepson Flora Project. Propogation from seed information provided by the Santa Barbara Botanical Garden from "Seed Propagation of Native California Plants" by Dara E. Emery. Sources of plant photos include CalPhotos, Wikimedia Commons, and independent plant photographers who have agreed to share their images with Calscape. Other general sources of information include Calflora, CNPS Manual of Vegetation Online, Jepson Flora Project, Las Pilitas, Theodore Payne, Tree of Life, The Xerces Society, and information provided by CNPS volunteer editors, with special thanks to Don Rideout. Climate data used in creation of plant range maps is from PRISM Climate Group, Oregon State University, using 30 year (1981-2010) annual "normals" at an 800 meter spatial resolution.

Links:   Jepson eFlora Taxon Page  CalPhotos  Wikipedia  Calflora


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