I struggled for a long time with how to begin this entry. I think because the story I’m about to tell feels like validation of so many of my goals for this yard and reasons I want natural things close by: attracting wildlife, increasing biological diversity, watching the ways species interact with each other and, most audaciously, providing support for threatened populations and species. I planted milkweed this year, and a few weeks ago monarch butterflies started showing up in my yard, and a few days ago I found monarch caterpillars munching down on my milkweed plants. Unbelievable! Whenever I replay that chain of events I’m left speechless. I didn’t know where to start, literally.
So why monarchs? And why milkweeds? There is evidence that many different insect species have suffered serious declines in recent decades, primarily from habitat loss, but of all insects the plight of the monarch is the best publicized. Monarch populations are pretty easy to count because the entire species gathers in hyper-dense colonies every winter, and recent counts suggest the species may have declined by 90% from mid-century levels. And the decline of the monarch appears to be all about the decline of milkweed. The spread of agriculture and the proliferation of glyphosate-resistant (the chemical in Roundup) crops has allowed agriculture operations to blanket spray fields, dramatically reducing the amount of some of our most common agricultural weeds across the country, milkweed being one of them (follow the links to or see the end of this article for information on a 2012 Insect Conservation and Diversity study and a 2014 Journal of Animal Ecology abstract showing these connections). Monarch butterflies feed on the nectar of many flowers but lay eggs exclusively on plants in the milkweed family (Asclepias). Ingesting the sap of the milkweed plant makes the caterpillars distasteful to birds, an effect that is residual through metamorphosis into adults. The yearly monarch migration is actually several generations reproducing and following the successive blooms of milkweed plants north from Mexico through the warming continent up to Canada, until the year’s last generation flies direct all the way back to Mexico, an unfathomable two and a half to three thousand miles on tissue paper thin wings and insect metabolism.
When I went to the nursery in the spring, exploding with optimism about my new gardens, I excitedly picked out two swamp milkweeds (Asclepias incarnata). But when I brought home my two milkweeds I grew a little skeptical. I started looking around at all the grass and it hit me how far away the nearest weedy field is. A half mile? A mile? It’s safe to say there are no other milkweeds near my house. How is a group of insects flying across the country supposed to cruise over Louisville and not only take notice of two lonely plants in my backyard but decide they are worthy of a visit? I quickly quelled my pessimism by assuring myself the two tiny plants would be the start of a milkweed patch that, one day, would be grand enough to warrant the attention of whole swarms of monarchs.
I was late getting the new garden dug and the milkweeds sat in their small pots for 3 weeks. And when I finally put them in the ground a wind blew one over on the first day. The other eventually got infested with aphids and never flowered (I suspect but am not sure if the aphids and the lack of flowering were connected). Despite my neglect and the late start the milkweeds grew like, well, weeds. The only other plants that came close to matching their rate of growth were the coneflowers. Even the one that fell over and was growing part sideways was 3 feet tall by mid-summer. And then, one day in late July, to my astonishment I saw a monarch flitting across my yard. It made a few circles and settled on the flowering swamp milkweed. I was blown away. Ten minutes later a second monarch joined the first. For the next month I saw one or two monarchs about every time I was out in the yard. The still skeptical part of me thought I was probably seeing lots of viceroys, the classic monarch look-alike, but then on the 25th of August while doing a mix of admiring and being repulsed by the aphid infestation I saw a monarch caterpillar. I eventually found four: all of them chunky, chowing away. They were certainly unfazed by the aphid problem.
Is this how easy it is? Stand in any city or suburb, look out over the expanses of pavement, roofs, and turf grass broken by little patches of agricultural weeds and here and there trees, and the notion that we can coax meaningful wildlife and significant biological diversity around our urban homes starts to feel silly real fast. The feeling might get worse when, surrounded by those vast lawns and vaster roads you realize the beginning of your new garden is a 12 by 20 inch tray of tiny potted seedlings. But oh what a beginning! I have no idea how the monarch butterflies found the two plants in my yard. Does it speak to their persistence as searchers, combing every inch from Mexico to Canada for places to reproduce? Does it speak to how few milkweeds remain that two so all alone warranted a stop? Or do monarchs add to their superhuman qualities the ability to identify one species of flower from another as they fly over the landscape?
Watching the butterflies flit around my yard, finding the caterpillars, it sure made me feel good. I started to feel like Ray Kinsella from Field of Dreams, hearing whispers in the humid, sticky Kentucky evenings, “if you plant it, they will come.” The unlikely connection I watched form in my backyard between a few butterflies and two specific plants is a testament to how much wonder has been lost from our lives by pushing wild things out, and a demonstration of its potential to come back. Let it be a mantra: don’t worry about the monarchs doing monarch things, just plant some milkweed, or blazing stars, or babtisia. See what comes. Have faith. I couldn’t help myself, I bought three more milkweeds for this fall and then, as a long term investment, a pack of seeds. Everything starts somewhere.
Studies cited on monarch butterfly decline:
1.Flockhart, D.T., Pichancourt, J.B., Norris, D.R., & Martin, T.G. (2014) . Unraveling the annual cycle in a migratory animal: breeding-season habitat loss drives population declines in monarch butterflies. Journal of Animal Ecology, 84(1), 155-165.
2. Pleasants, J.M. & Oberhauser, K.S. (2012). Milkweed loss in agricultural fields because of herbicide use: effect on the monarch butterfly population. Insect Conservation and Diversity, 6(2), 135-144.