How and when do I harvest the seeds from the pods?
Thank-you for contacting Toronto Master Gardeners with your question.
Butterfly weed (Asclepias tuberosa) seeds should be harvested in the fall. They can be sown directly in the garden (in the fall, as would happen if left to seed naturally) or started indoors during the winter after a period of cold stratification. Seed will germinate upon being shifted to 21°C after 90 – 140 days of moist, cold stratification at 10°C. Seed requires light to germinate. (Because butterfly weed dislikes having its roots disrupted, direct sowing is probably the most reliable method of propagation.)
A few additional culture notes: Keep butterfly weed well-watered through its first season; after that, it will be fine pretty much left on its own. Butterfly weed doesn’t require fertilization. A topdressing of compost once per year around the plant is sufficient.
For more information on the stratification process, please take a look at this website:
The website below gives information on butterfly weed and other related milkweeds: