Butterfly weed is a perennial wildflower native to North America. Contrary to the plant's name, it is not considered a noxious weed, but is valued for the deep orange, red and yellow flowers which attract Monarch butterflies. Butterfly weed plants can grow up to 3 feet in height and produce their famous flowers in spring through early fall. They are easy to grow from seeds in the home garden and require only minimal care once established.
Select a planting location which receives at least six hours of direct sunlight per day and has sandy, well-drained soil. Sow butterfly weed seeds in early spring by sprinkling over the soil. Rake lightly to cover and tamp down with a flat board to prevent seeds from being washed away.
Water immediately after planting seeds to ensure good soil contact. Continue watering once plants emerge any time the top inch of soil is moist and crumbly to the touch, usually about once per week. Avoid overwatering, as butterfly weed is drought tolerant but will not thrive in wet soil.
Spread a 2- to 4-inch layer of mulch over the soil around butterfly weed in mid-fall. This will help prevent frost damage during cold winters, conserve moisture and reduce weed problems. Replenish the mulch each fall as necessary, but don't worry if the layer diminishes in spring and summer.
Mark butterfly weed's location in fall before the plants die back for the winter. Use plant labels or spring flowering bulbs if desired. Butterfly weed is slow to emerge again in the spring, and marking will help prevent root damage from accidental digging.
Remove the first set of butterfly weed flowers as they fade to encourage another bloom. Allow the second set of flowers to set seed for additional plants. Flowers first form fruit or seedpods, which split open and drop seeds. The seedpods may be removed or left to self sow as desired.