Butterfly weed - Asclepias incarnata
Hi, I'm in Ellicott City and I've been trying to establish butterfly weed to attract monarchs. The deer destroyed my plants right after I discovered caterpillars last year. So I moved the plants to more deer proof area in my yard. The plants are somewhat invasive - they are coming up everywhere and I will need to thin or move. I have caterpillars on most of the stems so I don't know what to do. What is the life cycle of the butterflies in relation to the butterfly weed? Are there eggs? Do they overwinter? When can I safely move or thin the plants? Thanks.
The common milkweed (Asclepias syriaca) does spread fairly aggressively. You could transplant it in early spring or late fall. Monarch eggs do not overwinter on the plants. The egg stage lasts only about 3-8 days, depending on the weather. They are in the caterpillar stage 9-14 days and the pupal stage 8-15 days. The adults emerge in late summer/fall and migrate.
The following web site has a nice description of the monarch lifecycle.