Place the butterfly weed seeds in a plastic bag filled with 1 cup of moistened perlite. Store the bag inside the refrigerator for three months. Mist the perlite with water every few days to keep it from drying out completely.
Transplant the butterfly weed into a permanent bed in spring just after the last frost. If planting butterfly weed in clay soil, dig in 2 to 4 inches of compost to lighten the soil, or consider building raised beds to increase drainage.
Arrange the starter pots on a propagation mat near a source of bright, indirect light such as near a partly shaded south-facing window. Set the temperature on the propagation mat to 86 F during the day. Turn it off at night.
Watch for germination in two to three weeks. Turn off the propagation mat one week after the seeds sprout. Move the pots into a cold frame outdoors or against a south-facing wall with noonday shade.
Prepare peat or other biodegradable pots before removing the butterfly weed seeds from the refrigerator. Fill 3-inch starter pots with a mixture of half seed-starting compost and half coarse sand. Moisten the mix and press it firm.
Gather the butterfly weed seeds in late summer or autumn, once the pods dry to a light, rosy-beige color, but before they split open. Put on rubber gloves before handling the pods to protect your hands from the mildly toxic sap.
Leave the bucket outdoors for two or three days to let the fluff blow away. Stir the seeds occasionally to loosen more fluff. Do not worry if some of the fluff remains, since it won’t inhibit the germination process.
Deadhead spent flowers to keep your plants blooming for longer. You can leave some flowers on to develop into seed heads that look attractive during the winter months, but be aware that milkweeds spread by seed.
Here’s everything you need to know about how to grow and care for butterfly weed.
You don’t need to worry about watering or caring for the seeds through the winter. The cold and moisture that naturally come from snow and rain will tell them when to start growing.
Planting Butterfly Weed
Plant outdoors after all danger of frost has passed. Select a spot that gets full sun and has well-drained soil. Amend soil with compost if needed but little other preparation is required.
Butterfly weed is not invasive, but it will start to spread in your garden if unattended to. You can either clip off seed heads before they open and drop seeds, or you can simply pull up any seedlings that have sprouted in the spring.
Then, sow the seeds 4-6” inches apart (you can thin them in the spring when they sprout).
If you grew your own seedlings in peat pots, you can plant them as is. The pot will break down in the soil over time, but you can gently tear the bottom off to allow the roots to get through more easily.
Because the Butterfly Weed is adaptable to zones three through nine, it can thrive in a variety of different temperature and humidity settings. Generally, the plant emerges in late spring, hitting its peak bloom during the warmer summer months and drying on the stem throughout the autumn and winter. It also tolerates heat and drought well.
Butterfly weed is a must-have plant for green thumbs looking to coax its namesake beautiful winged insects into their garden. Also known as Asclepias tuberosa, orange milkweed, pleurisy root, and yellow milkweed, the plant can grow to be anywhere from one to two feet tall and is characterized by glossy green leaves and clusters of bright orange-to-yellow blooms that are rich with nectar and pollen, which in turn attracts butterflies, along with bees, insects, and hummingbirds, all summer long. First grown in the prairies of the Midwestern United States, Butterfly Weed boasts a long medicinal history as well—Native Americans used to chew the roots as a remedy for pleurisy and other pulmonary issues, and they can also be brewed into a tea that can then be used to treat diarrhea and other stomach ailments. Butterfly weed should be planted in the early spring (after the final frost)—it will be slow to emerge, but will grow quickly once it does, hitting peak height and bloom in mid-to-late summer.
Chances are there are more finicky flowers in your garden than the Butterfly Weed, so feel free to allow them to dictate the soil composition—when it comes to this plant, you don’t have to stress. Butterfly Weed can prosper in a variety of soil conditions and compositions, from clay to gravel, and generally prefers a neutral to slightly acidic pH.
The low maintenance Butterfly Weed does not require any additional fertilization—in fact, doing so can harm the plant, so it’s best to just let it do its thing.
During its first year of life (or until new plants start showing mature growth), you should maintain a moist soil environment for the Butterfly Weed. Once the plant appears to be well-established, you can cut back to watering it only occasionally, as it now prefers dry soil.
Choose a spot in your garden to plant your Butterfly Weed that boasts hours of bright sunlight daily, as this plant loves to soak up the rays. Full-sun is definitely your best bet, but the hardy plant can tolerate a few hours of shade too.
Typically, the easiest and most successful way to add Butterfly Weed to your garden is to grow it from seed form. Plant fresh seeds in fall for growth the following spring, or allow any established Butterfly Weeds already in your garden to do the work for you. Beginning in late summer or early fall, the plants should start to develop seed pods in place of their blooms. If left on the stem, the pods will eventually burst and the seeds inside will be blown throughout your garden, allowing them to establish themselves in the soil in time for the following year. If you’d rather have more control over the eventual location of any new Butterfly Weed plants, you can remove the seed pods from the plant before they burst open and simply plant new seeds by hand instead.