Many insects use milkweed at some point in their life cycle. Many people believe Milkweed to be toxic, so they avoid planting it, especially if they have small children or pets that they fear may try to put the leaves in their mouth. Samuel Thayer wrote an excellent book about wild edibles called the Foragers Harvest. In this book he discusses the common milkweed plant and eludes to it being edible and even quite tasty. To test this theory I pulled a milkweed leaf off of a particularly healthy looking plant. I broke the leaf open to reveal the sticky, milky substance from which this plant gets it's name. I put that leaf in my mouth and the only thing that happened.......I glued my lips closed! That milky stuff is better than superglue! I did not get sick, or even get a tummy ache. Would I recommend a salad made of this plant, probably not, but I don't believe you have anything to fear in planting it in your yard. The benefits far out weigh any risks.
I encourage these plants that make it into our garden, most likely seeded there by the wind. I leave them alone and watch the insect activity all season long.Everything from butterflies (Monarch's), to beetles, aphids, and true bugs) Look below for some of the different species that visit my milkweed.
(Small Milkweed Bug)
This pretty orange and black bug is the Small Milkweed Bug (Lygaeus kalmii), they belong to the order of insects called Hemiptera (True Bugs). Also called Common Milkweed Bug, which may be more of an accurate name, because they certainly are common. Each year I find them in large numbers on the milkweed growing around our farm. There is another True Bug called the Large Milkweed Bug (Oncopeltus fasciatus) that utilize milkweed, these too are very common, maybe more so than their smaller cousins. Each summer I have hundreds of these bugs in various stages of development. These two species look similar, they are both orange and black. The small milkweed bug has a "heart-shaped" black spot on its back, whereas the large milkweed bug has a broad black band across it's back. (picture 6)
(Large Milkweed Bug Nymphs)
(Another Large Milkweed bug nymph....light orange phase)
(Large Milkweed bug nymphs in various stages, normal color phase)
(Newly molted Large Milkweed Bug)
(Large Milkweed Bug adult)
Probably the most famous of all insects that use milkweed as a host plant are the Monarch Butterflies. These unmistakable orange and black butterflies make their northward journey out of Mexico or Southern California. After stopping in Texas, Arizona and various other southern regions to lay their eggs on milkweed they will perish. The eggs hatch and the tiny caterpillars grow fast on a diet of milkweed. After pupating, the newly emerged adults will once again journey north. This time they will stop in the midwest, leaving their eggs on the milkweed plant and once again perishing soon after. The adults that come from these eggs continue north, some making it as far as Canada. After mating, laying eggs and dying, their offspring will make the long journey to Mexico and Southern California. Miraculously none of these monarchs have ever been to Mexico or California, yet they seem to be pre-programed to know exactly where their ancestors came from. There are ongoing studies that are trying to make sense of this enormous feat. These adult monarchs will spend the entire winter living in isolated portions of Mexico. This generation will be the longest lived, and are capable of living 6 or more. The cycle will begin again with the return of warmer weather in the spring. No one knows for sure why this last born generation has the capability to live so long, yet subsequent generations will live only a few short weeks. Planting milkweed in your yard will certainly encourage these lovely butterflies to stop off in your yard and make use of this host. Milkweed is the only known host plant of Monarchs. The chemical makeup of the plant gives monarchs a toxicity that sees them through all stages of development. Birds, and other creatures have learned, I'm sure by trial and error, to give monarchs a wide berth. Stomach upset and vomiting are not much fun.
Another common insect to use milkweed are aphids. Now I know not everyone loves aphids, especially gardeners and green house owners, but there is something that does like aphids, very much in fact. LADYBUGS! Each year tiny yellow aphids make their way to the milkweed and the ladybugs follow suits. It is like an all you can eat buffet of tiny yellow morsels that the ladybugs go gaga over.
Even this differential grasshopper got in on the action and used this milkweed stem as a perching post for shedding it's skin for the final time.
Hidden in the foliage of the milkweed is this Red Milkweed Beetle. These beetles are also quite common on milkweed plants. They are one of the cutest of all the insects. One very cool feature of this beetle is it's antennae, they grow up right between their eyes! The tiny metallic crab spider hung out on the milkweed for several days scouting for succulent bugs to feast on. I am thinking this much larger beetle may be a bit too much. I think it is a case of your eyes being bigger than your belly.
(Red Milkweed Beetle)
So this spring when trying to decide what new plants to try in your garden, consider the milkweed, the bugs will thank you.