Create a Healthy Habitat to Sustain North America’s Most Beloved Butterfly
By Xerces Society, Storey Publishing, 2021
Reviewed by Sara Bothwell Allen
“Monarch butterflies can only eat milkweed” is the truism you’ve heard since you were a child that is colorfully refuted throughout the Xerces’ Society’s new book 100 Plants to Feed the Monarch a follow up to 2016’s 100 Plants to Feed the Bees. This new volume’s focus on how to provide nutrition for the charismatic butterfly is timely. As the populations of the Monarch (Danaus plexippus) have dropped precipitously in size in recent years, recreating their habitat all along their migration routes will be crucial to their survival. Public engagement towards saving the Monarch is increasing thanks to education programming. This book provides gardeners, both novice and experienced, the information they need to make their home gardens or community spaces valuable parts of the Monarch’s global support system.
This book is primarily a reference guide to the many species of milkweed (Asclepias species)—that’s right, the many species of milkweed—that meet Monarchs’ very particular needs in the larval (caterpillar) stage and the many, many genera of plants that provide nectar necessary for the adult (butterfly) life stage. However, Part One (the first two chapters) is a valuable read before you start planning any changes in your garden.
The first chapter describes the monarch’s life cycle and dramatic migration story, both of which are important to understanding why habitat loss and insecticide use have been so devastating to their populations. The chapter also explains how we can make contributions that will help, wherever we live across the continent of North America. Accompanying this information are exquisite photographs and illustrations. Did you ever wonder how to distinguish a male monarch butterfly from a female one? Or how to distinguish a Monarch from its copycats, such as the Viceroy? Aside boxes throughout this chapter teach you what to look for on these and other interesting topics. The language used is accessible to a general audience, and scientific terms are explained clearly. This chapter also mentions the danger of three non-native, invasive swallow-wort species, which can end up being nutritional traps—when monarch eggs are laid on swallow-wort, the caterpillars may try to eat it but cannot develop. With black swallow-wort appearing here in the metro west area of Boston, I’m glad this book will draw attention that encourages gardeners to remove it wherever it appears.
The second chapter is delightfully upbeat, focusing on how to create and protect monarch habitats. The most important point to take from this chapter is to be sure to plan your garden’s blooms to align with the timing of the monarch migration. Southern states’ spring-blooming flowers are helpful, but where I live in the northern states, late summer and fall blooms are needed. This book does not argue against planting spring flowers in northern states, which no doubt their Feed the Bees book promotes but instead urges us to plan our gardens to include bloom times that will feed Monarchs. A variety of ecological, aesthetic, and practical sections round out the rest of this chapter.
Part Two (chapters three through six) comprises the reference guide to each of the 100 plants to feed Monarchs that you’ll return to for your garden planning or as your entrée to botanical travel fantasies. (I’d love to see some of the beautiful milkweed species I’ve never seen before! So many different leaf forms and flower colors! Their range maps are helping me plan my itinerary.) The photos are beautiful throughout all four chapters but are especially helpful in distinguishing among each milkweed species (chapter three—31 species). The nectar-providing wildflower (chapter five—44 entries) and shrub/tree (chapter six—22 entries) sections are mostly genus-level representations, so particulars about the color, size, and other habits will end up being more variable. Chapter four is probably the most radical section of the book, sharing information about three genera of near relatives of milkweed that can also serve as monarch caterpillar host plants! So much for “Monarchs can only eat milkweed.” I admit to being disappointed that the range maps indicate that I will not be able to grow any of them. Instead, I’ll content myself with aiming for the five species of milkweed that are in range here—some, but not all, currently growing in my yard.
A uniform format is used throughout the chapters in Part Two: Plants are listed alphabetically by common name. Each entry contains one or more beautiful photographs, common and scientific names, text describing the plant, a range map, uses, and suggested companion species. A yellow banner across the bottom of these pages includes all the basic gardening information (exposure, soil moisture, bloom time, flower color, plant height) that you’ll want to find easily, as well as whether each species is easy or hard to find commercially. It’s a beautiful reference guide, but here and there contains interesting additional information, such as the historical use of A. tuberosa’s seed floss. Its use as a reference guide would be improved if the banner color varied by chapter.
Care was taken to include a wide variety of native plant species throughout the last two chapters (the nectar-providing plants), providing many options for gardeners across the geographic ranges of the United States and southern Canada. Xerces included species with bloom times that stretch throughout the season so that the attentive gardener can plan for floral resources throughout the growing season. Because of this, the entries in the shrubs/trees section in the California range are strongly reminiscent of the recommended plant lists for California farmland hedgerows that include continuous floral resources for beneficial insects.
This guide is not prescriptive, however. Each of us must bring our own knowledge of local conditions, map it to when Monarchs will pass through our area, and select plants best suited to both. Deeply thinking about what to plant and for whom makes the success of watching butterflies visit the flowers more gratifying and a part of a nationwide patchwork of efforts to save this remarkable species.
About the Author
Sara Bothwell Allen, Ph.D., is an insect ecologist and has taught at the University of California at Santa Cruz and San Jose State University. She is currently involved with k-12 outdoor science education and a community-based effort to protect local ecology with Lexington Living Landscapes (www.lexingtonlivinglandscapes.org.)
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