Butterfly Weed Gay Butterflies - Asclepias tuberosa - flowers in shades of red, yellow, orange, and bronze Heat and drought tolerant, 3 ft. tall plants produce large 6 in. clusters of vibrant summer flowers. Colors include shades of red, yellow, orange, and bronze. Flowers attract swarms of butterflies, are excellent for cutting. Winter hardy to zone 3. Germination uneven over a period of 21-90 days.