In our continued work to help increase the availability of plant materials for pollinator conservation, Xerces staff conducted propagation and outplanting trials for Asclepias cordifolia (heartleaf milkweed). This species provides critical pollen and nectar resources for monarchs and other declining pollinators. Heartleaf milkweed is also a key early-emerging host plant for monarch butterfly caterpillars. This species has been challenging for nurseries to grow, and therefore, currently has very limited commercial availability and is not widely used in restoration projects.
This four-page report details the results of the 2024–2025 trials testing the efficacy of two container liners as well as the survivability of seedlings planted at two intervals.