Monarch butterflies are in serious trouble. Their populations have crashed and are at an all time low, and experts fear that this iconic black and orange butterfly species could disappear altogether if action isn't taken.
Monarch butterfly on milkweed. Photo by Rick&Brenda Beerhoorst via Flickr Creative Commons.
Monarchs, like all butterfly species, require host plants where they lay their eggs and where their caterpillars feed. Through the process of co-evolution, over hundreds of thousands of years each butterfly species has evolved immunity to the chemical defenses of just a limited number of plants. These are that species' host plants.
In the case of monarchs, milkweed (Asclepias spp.) is their only host plant, and unfortunately, we have done a bang-up job at a massive elimination of milkweed from coast to coast. Like many native plants that support wildlife, milkweed has gotten a bad reputation as a "weed." The default position of both conventional commercial agriculture as well as conventional home gardening is to eliminate it.
Monarch caterpillar on milkweed. Photo by Brian Garrett via Flickr Creative Commons.
With the help of herbicide-resistant GMO crops that allow industrial farmers to spray massive amounts of chemicals to eliminate every last milkweed, and the emphasis of the home gardening industry on exotic ornamental plants that don't support wildlife over native plants like milkweed, we have been tremendously successful at wiping out milkweed. And the monarchs are suffering.
It's not all bad news. We each can all do something to turn around this dire situation: PLANT MILKWEED IN YOUR GARDEN! I'm not exaggerating with my capitalization. What we do in our gardens can literally save this beautiful butterfly species from oblivion. Add milkweed into your flower beds, plant it in containers on your patio, or if you have the space, grow a wildflower garden with milkweed and lots of othe native plants.
Swamp milkweed seed pods in my garden. Photo by David Mizejewski.
There are a few dozen species of milkweed native to North America. Many are actually beautiful ornamentals that are increasingly being sold in garden centers. You can get seed packets for some species as well. You can collect milkweed seeds (if you can find any wild plants) and grow them yourself. Not only is milkweed the host plant for monarch caterpillars, it's also an excellent nectar plant for adult butterflies and many other pollinators.
I'm currently growing two kinds of milkweed in containers in my urban backyard: swamp milkweed (Asclepias incarnata) and butterflyweed (Asclepias tuberosa). These two species are found over much of the continent and are the two you're most likely to see in your garden center. Mine are part of the American Beauties Native Plants line.
So far, I haven't had any monarch caterpillars. Monarchs are one of the few migratory insects. The last generation to hatch in late summer will delay sexual maturity and migrate down to a few locations in the mountains outside Mexico City, or scattered locations in central California where they'll go dormant for up to five months before migrating back across North America. I'm keeping my fingers crossed that in the coming weeks, my milkweeds will serve as host to this last generation of the season.
Swamp milkweed seed pods. Photo by David Mizejewski.
Even if they don't this year, I've begun gathering seeds from my milkweeds. I will keep them in the refrigerator for a couple of months to simulate winter weather conditions the seeds need in order to germinate, and then plant them indoors around January. By the time spring rolls around, I'll have dozens of small milkweed plants that I can add to my garden and share with my friends.
Saving a species can really be that simple, but we all need to do it for it have an impact. I hope that you'll add milkweed to your garden and help save the monarchs!
Plant a Garden for Monarch Butterflies with the National Wildlife Federation.