Tropical Milkweed, Asclepias curassavica

Aphids make Tropical Milkweed Less Inviting to Monarch Butterflies

The article makes a suggestion for the home gardener for controlling oleander aphids on milkweed.

Asclepias curassavica with Aphids

Tropical Milkweed, Asclepias curassavica

Tropical Milkweed Asclepias Curassavica is not a native plant to Florida. Many consider it harmful to butterflies. Things to consider are presented below. If you decide to have this plant in your central Florida yard, it is recommended that you cut it back in the fall. When the plant resprouts in the spring it should be OE-free. If you don't cut it back, OE builds up in the plants and becomes progressively more harmful to Monarchs.

In Florida, this plant is spreading to natural areas where it will not be cut back, but continue to build up OE increasing the risk to Florida monarchs.

Florida Experts

"Dr. Jaret Daniels of the University of Florida believes that the spread of the non-native tropical milkweed may be causing monarch populations to persist longer than they naturally would, making them more vulnerable to OE and thus presenting a risk to other monarch populations."

While not on the Florida Exotic Pest Plant Council (FLEPPC) list (yet), this plant has spread into natural areas and is often seen on roadsides and in open pastures. It is commonly sold and frequently mistaken as a native species.

Link to the full article at FANN written by Roger Hammer, Posted on August 22, 2011

Quote from Florida Wildflower Foundation:

"...prolonged breeding can foster higher than normal infection rates by a lethal protozoan parasite, Ophryocystis elektroscirrha (OE).

Are non-native milkweeds killing monarch butterflies?
Posted on January 12, 2012 Florida Wildflower Foundation

Monarch Alliance

The Monarch Joint Venture (MJV) is a partnership of federal and state agencies, non-governmental organizations, businesses, and academic programs working together to protect the monarch migration across the United States.

Potential Risks of Growing Tropical Milkweed

Why We No Longer Carry Non-Native Tropical Milkweed

Article from Native Nurseries in Tallahassee, Florida April, 2020

The article includes information on native milkweeds

Xerces Society

Tropical Milkweed—a No-Grow By Justin Wheeler on 19. April 2018
Monarch Nectar Plants: Florida
Roadside Milkweeds of the Southeast - download PDF
2019 Three Research Papers - scroll down several paragraphs to find research summaries

Monarch Joint Venture

Our mission is to protect monarchs and their migration by collaborating with partners to deliver habitat conservation, education, and science across the United States."

Q&A about research related to tropical milkweed and monarch parasites

"We think that the risk is real enough and there are enough milkweed species that don't have this effect that it makes more sense to plant natives. If people want to keep planting the non-native tropical milkweed, they should understand and be comfortable with the likely consequences. "

Commercial Use of Curassavica

Monarch Butterfly Garden LLC's website with advertisements summarizes the situation. The latest link date is 2016. This site sells butterfly products. Calls information coming out about curassavica a "smear attack".

Cutting back once in the fall does eliminate the plant from spreading to natural areas.

North American Butterfly Association (NABA)

Formed in 1993, the North American Butterfly Association (NABA), a not-for-profit membership organization, is the major North American organization promoting the conservation of butterflies and their habitat. NABA focuses its efforts on educating the public about the importance of butterflies and their habitats and on conserving butterflies, both to the benefit of humans and our environment.

In recent years, the focus of the program has highlighted the need to use regionally native plants when developing habitats for butterflies. NABA’s regional butterfly garden guides, one of the primary features of the program, are in the process of being updated to include regionally native plants as their primary focus. 2017

Smithsonian Magazine

Science

Monarchs that ‘drop-out’ of the migration game pick up more parasites

Texas Butterfly Ranch

Tropical Milkweed OK for Monarch Butterflies, "Just Cut the Dang Stuff Down” target="_blank"