Milkweed

Question

when to plant milkweed for butterflies in zone 7 (San Jose, California)

Answer 1

Here is a good article on whether growing milkweed for monarchs is a good idea in California. It isn't as clear cut as one would imagine. If you decide to go ahead, follow the article's links to which particular type of milkweed to grow and where to find it. The species is very, very important as monarchs specialize to the milkweed that is native to an area and will not visit other milkweeds. A local native plant nursery will also have good advice and products. https://baynature.org/article/plant-milkweed-save-monarchs/