Milkweed
Flower
Sow indoors 6-8 weeks before the last frost date and transplant or direct sow towards late spring. Optimal soil temperature for germination: 10-25°C (50-75°F). Seeds should sprout in 7-35 days. Asclepias may benefit from stratification: Seeded trays are wrapped in plastic and refrigerated for two to three weeks before being placed over bottom heat. This may result in more even and speedier germination.We have had success direct sowing in March, with blooms the first year. In our experience, returns with vigour in the second year and begins blooming by June here on the west coast.
Milkweed
How to Grow:
Flower
Timing:
Sow indoors 6-8 weeks before the last frost date and transplant or direct sow towards late spring. Optimal soil temperature for germination: 10-25°C (50-75°F). Seeds should sprout in 7-35 days. Asclepias may benefit from stratification: Seeded trays are wrapped in plastic and refrigerated for two to three weeks before being placed over bottom heat. This may result in more even and speedier germination.We have had success direct sowing in March, with blooms the first year. In our experience, returns with vigour in the second year and begins blooming by June here on the west coast.
Starting:
Barely cover the small seeds using sterilized seed starting mix. Space transplants 30-60cm (12-24″) apart.
Growing:
For many years several Asclepias species were listed as invasive weeds because of their sometimes aggressive spreading by underground rhizomes and their giant, dandelion-like seeds. The seeds emerge from very conspicuous pods which are easily removed before they dry and crack. As the population of wild Asclepias diminished, so did the populations of many butterflies that depend on them as food and nursery plants (including the endangered Monarch). Now that they have been de-listed, we encourage home gardeners to grow them with the advance knowledge that they can spread. Try growing them in a large container like a half barrel, and be conscious of the seed pods as they develop. In short, please be responsible with Asclepias species.
Harvest: