Can milkweed pollen get on nearby raspberries making them inedible?
Question:
I have a milkweed question. Some sites I’ve read say all parts of the plant are poisonous. Others say you can eat it. I don’t want to eat it but I have a bunch growing in our raspberry patch. Do I need to worry about milkweed pollen getting on the berries?
Answer:
You are correct that milkweed (Asclepias) is toxic–while it was historically used in alternative medicine for a variety of ailments, this practice is no longer advised as the plant contains known toxins to mammals. But your question about pollen on nearby plants presents a great opportunity to delve into a little bit of botany! Milkweed is a member of the plant sub-family Asclepiadoideae, and one interesting feature of the group is that it does not produce loose pollen like most plants, instead constraining its pollen to tiny internal sacs called pollinia (the other group of plants known to do this are the orchids) that are linked to the carpels they will eventually pollinate. When pollinators move from flower to flower on milkweed, their legs detach whole structures containing female and male parts (i.e., the pollen) that later fall to the ground to germinate. As a result, you won’t have a cloud of pollen released onto nearby plants, like your raspberries.
I suppose it’s technically possible that pollinators might transfer the detached milkweed floral structures themselves to nearby plants, but even if they did, their number would be orders of magnitude fewer than a typical pollen rain. Wash your raspberries well (as you always should before eating) and enjoy the pollinators the milkweed attracts to your garden.