Native to the meadows of the eastern United States, butterfly weed (Asclepias tuberosa) produces bright orange flowers in summertime. These tiny blossoms are borne in clusters that attract both butterflies and bees, and some butterfly species lay their eggs on the plants to provide food for the caterpillars. This herbaceous perennial dies back after fall frosts and re-emerges in the spring once the ground has warmed considerably. Butterfly weed is an easy-to-grow wildflower in gardens across U.S. Department of Agriculture hardiness zones 3 through 9.
Choose an appropriate location for the butterfly weed in your landscape. This plant tolerates sandy, loam and clay soils that are well-draining, which means it never becomes soggy after rains. Also choose a spot that receives abundant sunlight, a minimum of six hours of direct sun rays daily.
Measure the size of the root ball of the butterfly weed in the container. Make a planting hole that is just as deep as the root ball, and twice the diameter.
Dig the planting hole with a garden shovel, overturning the soil and breaking up any clumps. Even though butterfly weed survives in infertile soils well, incorporating a little organic matter into sandy or clay soils improves the soil's texture and leads to a healthier plant.
Remove the plant from its container and place it into the planting hole. If any roots are compacted in the root ball, cut or tear the mass of roots in two or three places to encourage new roots to later form and grow outwards into the soil. Make sure the root ball is at the same depth as it was growing in the container--the top of the root ball must be level with the top of the planting hole.
Replace the soil into the hole, gently tamping it with your fingers around the root ball. Fill the hole until the root ball's top matches the overall soil in the garden. Do not plant the butterfly weed too deeply by piling excess soil atop the root ball or further buying the stem. Any excess soil can be used to make a shallow berm around the plant to create a moat or basin to catch irrigation water.
Water the newly planted butterfly weed with a sprinkling can or nozzled garden hose. Add 2- to 4-inches of water to the planting hole area, allowing it to soak in. This watering moistens the soil and compacts it, removing any air pockets.
Monitor the butterfly weed for one month after planting. Although drought tolerant once established, add water to the soil to supplement rainfall to keep the soil moist (never soggy). After one month's time, the roots should be growing and the need for watering diminished, but consider watering the plant during any stretches of time when rainfall is lacking and temperatures are hot. Try to avoid a wilting plant the first growing season.
Cut away frost-killed dried stems of the plant in late winter with a pruners to a height of 2 inches. This allows new growth later in spring to emerge without being impeded or masked by ugly brown stems. Shred the stems on the ground as it will further decay and provide nutrients to the roots of the butterfly weed. Alternatively, if you find the dead stems particularly unattractive after killed by frosts in autumn, you can prune them down then.