How to Plant Butterfly Weed Seeds
Sometimes called pleurisy root, butterfly weed (Asclepias tuberosa) is a perennial wildflower grown for its showy, reddish-orange flower clusters and textured, lanceolate leaves. A member of the milkweed family, it thrives throughout U.S. Department of Agriculture plant hardiness zones 3 to 9, where it is frequently added to butterfly gardens and native plant landscaping.
Butterfly weed and milkweed seed pods may be harvested and planted to support Monarch butterfly caterpillars. Butterfly weed grows well from seeds, which must be harvested in late summer and either sown immediately in the garden, or started in spring after a lengthy chilling process. The seeds are viable and will germinate with little care, although they must be planted at the appropriate depth to ensure successful sprouting.
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.
Before you begin to harvest the butterfly weed pods, sterilize your cutting tools. Dip the blades into a full-strength household cleanser, such as Lysol or Pine-Sol. Repeat between cuts to prevent the spread of diseases.
Snip off the pod using pruning shears. Slice lengthwise along the edge using a utility knife. Pry open the seed pods. Scoop out the seeds and fluffy matter inside and place it in a bucket.
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.
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.
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.
Make a 1/4-inch-deep planting hole in the center of compost mixture. Drop one butterfly weed seed in the planting hole. Cover it with a loose layer of compost. Mist the compost to settle it.
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.
Water the butterfly weed seeds whenever the compost feels barely damp when pressed. Apply the water by the spoonful or use a spray bottle to keep from dislodging the seeds.
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.
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.
Spread a 1-inch-thick layer of mulch around each plant. Water weekly to a 2-inch depth during their first summer, then cease supplemental irrigation.
Joe Pye Weed Seeds 6935
Joe Pye Weed Seeds 6935 (Eupatorium maculatum). This is one of our showiest native plants. Joe Pye Weed is another Carolinian Canada species that’s a bee, butterfly and hummingbird favourite. Tall single stemmed plants average 120 cm (4′) height and are loaded with fluffy, vanilla scented, showy purplish-white blooms for several weeks in July and August. Flowers form in terminal domed clusters up to 30 cm (12″) wide. A good wetland meadow plant as it tolerates constantly moist soils – also found along stream banks and marsh edges. Best in full sun but it will tolerate part shade. Perennial hardy to Zone 3.
How to Grow
4,400 seed/gram. Start seed indoors in a soil-less medium any time in late winter. Barely cover seed, moisten the growing medium and then place the container in a fridge or freezer for 3-4 weeks before bringing it back into the warmth. Keep at 15 C (60 F) for the 20 to 30 day (sometimes longer) germination period. After germination, grow on under lights at the same temperature then harden off and transplant outside to a sunny site with moist soil. Better yet, sow directly outdoors in mid-October in the site where it is to grow. This will allow dormant seed to be naturally stratified during the winter. This plant is slow growing and requires two years to flower when grown from seed.