In recent years, we have heard and read much about the declining monarch butterfly population due to eradication of milkweed in agricultural and urban areas. Milkweed is critical for the survival of monarchs. It is the only host plant for the monarch caterpillars which feed exclusively on the leaves of milkweed. And besides providing food for caterpillars, the leaves of the milkweed plant are the only place that the female monarchs lay their eggs. As milkweed plants gradually disappeared from the landscape, the monarch populations gradually declined. With the decline, there is urging to plant milkweed to support and increase the monarch population.
Back in the 1990s, I began an initial planting of the common milkweed (Asclepias syriaca) along our creek banks with seeds from a single pod that I found along the road side. In the 20 some years since, those few seeds have fostered a nice habitat for monarchs as they not only spread along the creek bank, but also into the surrounding pasture. This year I am once again on a mission to collect some pods, harvest the seeds, and eventually plant them. However, this time I have a partner; my 9-year old granddaughter loves monarchs and wants to do her part in helping their survival.
Fall is the perfect time to collect and plant milkweed. The first step is to acquire seed. Most milkweed species grow particularly well in undisturbed areas, so start by checking out roadsides, pastures, creek and river banks, railroad track beds, bike paths, highway medians, agricultural field margins, vacant land, cultivated gardens, and parks. In September the seed pods begin to turn brown, split, and open. The seed pod looks like a spiny, bumpy fruit. They begin light green in color and gradually over the summer turn yellow-green and eventually sage green to sage grey-brown. As they get to this later stage, they will start to split. This is the stage that you want for harvesting seeds. When the pod is opened, the seeds inside should be dark brown. If they’re green or light brown, they’re not mature yet and won’t sprout when planted. If you don’t see the split or aren’t sure about the color, you can gently push on the pod; if it splits easily and the seeds are brown, it is ready; if it won’t pop open easily, leave it for another time.
Remove the entire seed pod from the plant and place it in a paper or organza bag. Attached to the seeds is the coma, (white, hairy fluff also known as floss, silk, or plume) that is essential to the natural propagation of milkweed in the wild. The fluff enables the wind to scatter and disperse the seed over a wide area. Whether the seed is saved to share or use later or planted this fall, the fluff should be removed and it is best to do this before the pod fully opens and explodes. When the seeds are all compact inside the pod, it is easy to do by carefully removing the spine holding the fluff and running your fingers down it; as you do, the seeds fall out easily. Check out the Monarch Butterfly Garden website for a great video on how to do this. If the pod is more mature and already opening with the fluff beginning to take flight, place the pod in a paper bag and shake it vigorously; sometimes it helps to add some coins or washers to the bag to aid this process.
Milkweed needs a period of cold stratification to germinate so that is what makes fall an ideal time to plant milkweed as Mother Nature will do the work during the winter months. November is the best time in the Midwest to plant. The soil needs to be cold enough that the seeds won’t germinate, but not yet frozen. The location chosen should be sunny and an area where you can allow the milkweeds to spread naturally over time as they can become invasive in a perfectly manicured yard or flower garden. A bare patch of moist soil is best. Poke a shallow hole and drop in a seed or two. Cover, water, and lightly mulch for winter protection, and wait for spring. For more tips on planting, see Fall Planting Milkweed Seeds – 10 Simple Steps from the Monarch Butterfly Garden website. Another method of planting is by making and throwing out seed balls. To learn more about this method, see the article by the Iowa DNR.
If you miss the window for fall planting, the seeds can be planted in the spring, too. For additional information on keeping seeds over the winter and planting in the spring or other times, check out the Michigan State University publication, How to Collect and Grow Milkweeds to Help Monarchs and Other Pollinators.
Lastly, I would be amiss to not suggest that this would make a great 4-H project for any young person interested in monarch habitat. And for crafters, there are any number of ways to use the dried pods. In all cases, please be advised to wear gloves or wash hands frequently when working with milkweed or pods. Milkweed sap (looks like milk) can be an eye irritant, so take appropriate precautions to avoid this kind of discomfort.