Asclepias – Incarnata (Butterfly Weed)
This is a new addition to our growing from the US. They call it Butterfly weed, as it is absolutely irresistible to butterflies and bees. Pink or White flowers in flat umbels on long stems, growing to around 4 feet. I am not sure they will get that size here, but they are hardy and will go through our winter weather. They seem a little complicated to grow but we are quite confident. This plant will be a tremendous asset in any herbaceous border as it is so very different from anything we commonly have in the UK. They wake up around 4 weeks after our normal range of garden perennials, for no apparent reason other than they like a “lay-in”.
Sow indoors into moist sand and cold stratify. Move to -4-+4°C for 4 weeks. Then move to 20°C for germination. Germination takes 21-28 days. After germination grow on in cooler conditions. Transplant seedlings when large enough to handle to 8cm pots. Acclimatise and plant out once danger of frost has passed with 60cm spacing.
OR, Can be sown directly in autumn where the seed will be naturally stratified.