The plant tolerates dry soil but not heavy soil. Once established do not disturb butterfly weed unnecessarily. Butterfly weed is slow to start growth in the spring. Mark its location to prevent damage to easily injured dormant crowns. A taproot makes transplanting difficult.
Propagation is by seed or division in the spring.
The seed germinates in 3 to 4 weeks at 70 to 75 degrees. Plants may be planted in a cold frame in spring or fall. Fresh seed may need chilling. A cultivar can be found in the various seed catalogs. The sap is not as milky as some milk-weeds, being a bit thin and runny.