Growing Asclepias sullivantii (Prairie Milkweed) can be a rewarding experience, especially if you're interested in supporting monarch butterflies! Here's a guide to help you get started:
Site Selection
Sunlight: (Prairie Milkweed) thrives in full sun (at least 6 hours per day).
Soil: It prefers well-drained soil, but can tolerate a variety of soil types, including clay, loam, and sand. It does best in moist to average soil conditions.
Sowing Seeds Outdoors
Fall Sowing:
Sow seeds in late fall, after the first hard frost but before the ground freezes.
Prepare the soil by clearing any debris and lightly raking the surface.
Scatter seeds evenly over the soil surface.
Lightly cover seeds with a thin layer of soil (about 1/8 inch).
Water gently but thoroughly.
Seeds will germinate in the spring.
Spring Sowing:
Sow seeds after the last spring frost.
Prepare the soil as described above.
Sow seeds as described for fall sowing.
Keep the soil consistently moist until seeds germinate.
Starting Seeds Indoors
Timing: Start seeds indoors 8-10 weeks before the last expected spring frost in your area.
Stratification: (Prairie Milkweed) seeds benefit from cold stratification to improve germination rates. You can mimic this process by:
Mixing seeds with moist sand or vermiculite in a sealed container.
Refrigerating the container for 4-6 weeks.
Sowing:
Sow seeds in seed starting mix, about 1/8 inch deep.
Keep the soil moist and warm (70-75°F) until seeds germinate.
Transplanting:
Once seedlings have a few sets of true leaves, gradually acclimate them to outdoor conditions.
Transplant seedlings outdoors after the last spring frost, spacing them 1-2 feet apart.
Planting Depth
Whether sowing seeds directly or transplanting seedlings, plant them at a depth of about 1/8 inch.
Watering
Keep the soil consistently moist until seeds germinate and seedlings are established.
Once established, Sullivant's Milkweed is relatively drought-tolerant, but it appreciates occasional watering during prolonged dry spells.
Stratification and Scarification
Stratification: As mentioned above, cold stratification is beneficial for Sullivant's Milkweed seeds.
Scarification: Scarification (scratching or nicking the seed coat) is not typically necessary for Sullivant's Milkweed seeds.
Maintenance Tips
Mulching: Apply a light layer of mulch around plants to retain moisture, suppress weeds, and regulate soil temperature.
Deadheading: Remove seed pods before they mature if you want to prevent self-seeding. However, leaving some seed pods provides food for insects and adds winter interest to the garden.
Pest and Disease Control: Sullivant's Milkweed is relatively pest and disease resistant. However, watch out for common problems like aphids and spider mites.
Invasiveness
Sullivant's Milkweed is not considered invasive. However, it can self-seed in ideal growing conditions.
Additional Notes
Sullivant's Milkweed is a native plant to North America and is a valuable addition to pollinator gardens, especially those designed to attract monarch butterflies.
It is a hardy perennial that can tolerate a wide range of growing conditions.
Sullivant's Milkweed has beautiful pink to purplish flowers that bloom in the summer.
Remember to choose Prairie Milkweed varieties that are suitable for your specific climate and growing conditions. With proper care, you can enjoy the beautiful and beneficial blooms of Sullivant's Milkweed in your garden for many years to come.
