Asclepias curassavica 'Silky Deep Red' (Red Butterflyweed) - This is a darker, red-flowered form of the typically orange and yellow Butterfly Weed, also known as Tropical Milkweed, a tender semi-evergreen perennial prized for attracting butterflies, particularly the Monarch Butterfly, into the garden. Growing 3 to 4 feet tall by as wide, this plant has narrow 6-inch-long dark green lance-shaped leaves with a reddish hue on new growth. The flowers, appearing in late spring to late fall, are on long stems bearing 3- to 4-inch-long clusters of deep red and yellow flowers that like others in this family not only have a calyx row of 5 sepals and above this the corolla of 5 petals but also and additional of appendages covering the stamens called a corona. On this cultivar the petals are dark red and the corona a bright yellow. The flowers are followed by 3 inch long spindle-shaped seedpods that produces viable seed - this plant readily self-seeds to perpetuate itself within the garden.
Plant in full sun in a well-drained soil and give occasional to regular irrigation. Although tender to frost this plant is root hardy to at least 15 F. Mulch if gardening in climates experiencing harder frosts or keep in a container that can be brought indoors in colder climates. A good plant mixed with other tall perennials and the long stems are excellent for cutting. Cut back in the fall after all caterpillars are gone (often left leafless by them) but be wary of the milky sap, which can cause irritation and injury to eyes and is poisonous if ingested. An excellent butterfly nectar plant and attracts Monarch butterflies as an egg laying host as milkweeds are the sole food source for Monarch caterpillars (don't remove those fantastic large-horned, black and yellow-striped caterpillars).
Asclepias curassavica is native to South America but has become a naturalized weed in tropical and subtropical pastures, fields and disturbed areas throughout the world, including central and southern Florida. The name for the genus was one that Carl Linnaeus ascribed after Asclepius (Asklepios), the Greek god of medicine and healing because of the many folk-medicinal uses for the milkweed plants. The specific epithet means of Curacao (Dutch Antilles) in reference to its origin from this South American location. Other common names include Bloodflower, Swallow-wort, Hierba de la Cucaracha, Mexican Butterfly-weed, Scarlet milkweed, and Wild Ipecacuanha.
Habitat loss in both the United States and Mexico remains the biggest threat to the Monarch Butterfly but some studies indicate that native wilkweeds, such as Asclepias speciosa, are possibly a more healthy food source for monarch populations as the leaves of the native species are less likely to spread a protozoan parasite called Ophryocystis elektroscirrha, mostly because the native milkweeds do not become a year-round food source like the tropical ones, so encourage migration, which is argued helps control the disease because butterflies infected by the parasite are so weakened that they are not able to complete the migration journey. Under pressure from some conservation groups the California Department of Food and Agriculture (CDFA) took unprecedented action in classifying Asclepias curassavica as a B-rated noxious weed in 2022. This was quite unusual as it was not because the plant had actually become a weedy plant, but because of possible negative effects on the migratory behavior and health of populations of monarch butterflies in the state. While there are many in the scientific community that claim this reasoning is flawed (See the University of California Agriculture and Natural Resources report Tropical Milkweed Doesn't Deserve the Bad Rap), this action by CDFA means that means the state considers the species detrimental and counties can and have banned its sale. Though we still have plants growing in our garden we can no longer grow to sell the species Asclepias curassavica or the two named cultivars we previously did, this red one and the all yellow 'Silky Gold', but instead promote and sell the native milkweeds we continue to grow.
The information about Asclepias curassavica 'Silky Deep Red' displayed on this web page is based on our research conducted in the nursery's horticultural library and from reliable online resources. We also include observations made about it as it grows in our nursery gardens and other gardens we have visited, as well how the crops have performed in containers in our nursery field. We will also incorporate comments we receive from others and welcome hearing from anyone with additional information, particularly if they can share cultural information that would aid others in growing this plant. |