Butterfly weed grows as a low, 2-foot-tall shrub. It has attractive green foliage but its clusters of striking orange, red or yellow flowers are the real draw of this plant. The shrub flowers from midsummer through fall, attracting butterflies and other beneficial insects to the garden. Butterfly weed has a long taproot that doesn’t handle transplanting well. Starting the seeds indoors helps ensure germination and healthy early growth, but the plant must be transplanted outdoors before the long taproot becomes established.
Difficulty: Moderately Easy
Fill a plastic bag with moistened peat moss. Bury the butterfly weed seeds in the peat moss and seal the bag closed.
Store the bag of seeds in the refrigerator for 10 to 12 weeks. The seeds require this cold period to break dormancy and germinate.
Water a soil-less potting mixture until it is evenly moist throughout. Fill 5-inch-diameter nursery pots to within ½ inch of the rim with the moistened potting mixture.
Sow two seeds per pot, planting them approximately ¼ inch deep. Sprinkle the soil surface with water to moisten.
Cover each pot with a plastic bag. Set it in a warm, 70 to 75 degree Fahrenheit room to germinate. Germination takes approximately three to four weeks.
Remove the plastic bags once seedlings emerge from the soil. Move the pots to a warm, sunny window and water when the soil surface begins to dry.
Tips & Warnings
Transplant butterfly weed to its permanent bed by the time the plants have five to six leaves.
Butterfly weed can be transplanted outdoors in either spring or fall.
Purchased seeds usually are already cold treated and can be planted immediately.