Benefit Butterfly Populations While Bringing Beauty to Your Cook County Home Garden
May 21, 2024 08:06AM ● By Content Editor
By Jennifer Janasie for Boreal Community Media - May 20, 2024
Gardeners in Cook County who want to add beauty to their home gardens can expect butterfly populations to benefit with just a bit of planning. University of Minnesota Extension Master Gardener Maxene Linehan offers species-specific native planting recommendations to attract and support some of her favorite Cook County butterflies. “I personally enjoy Monarchs, who feed only on native milkweed (common milkweed, swamp milkweed, and butterfly weed) leaves during their caterpillar stage; but in their flying adult stage they feed on the nectar of native flowers such as liatris (a favorite), goldenrod, Joe Pye weed, asters, purple coneflowers, to name a few,” says Linehan. “I also enjoy (Canadian) Tiger Swallowtail butterflies, whose caterpillar eggs are laid on the leaves of trees: (such as) willows, (quaking aspen, and birches)...The adults sip the nectar of the blossoms of wild cherry, Joe Pye weed, (and) milkweed…among others,” she says.
A Monarch enjoying a snack on Swamp Milkweed (Asclepias incarnata) in a marshy area. Taken by Jennifer Janasie.
Experts suggest that as gardeners decide which plants to put in, they lean into our region’s list of native plants, and for good reason. “Native plants co-evolved with the climatic conditions and other species in a given region, which makes them well-suited to our gardens,” says the Monarch Joint Venture’s Habitat and Science Team. Due to this co-evolution, native plants provide native pollinators like butterflies with the specific habitat, nectar, and pollen resources that they need to thrive, according to the Team.
“Native flowers are usually better at attracting butterflies (and moths) than cultivars and "nativars" which are native plants that have been crossbred or developed by selective breeding for other characteristics like double flowers,” says Linehan. Double flowers can prevent butterflies from reaching nectar. “The scents flowers use to attract pollinators also might be reduced or lost when the flowers are crossbred or bred for other characteristics such as color,” she says. In other words, non-native plants are frequently not acknowledged as food sources by area butterflies (and other wildlife).
Some non-native plants might still attract butterflies. However, these plants might not present an equal amount of nutritional value compared to native plants. They also may not support the whole life cycle of native pollinators, according to the Team. “This is the case for monarchs which require milkweed to successfully reproduce, and in Minnesota, this should solely consist of native milkweed species,” the Team members say. Non-native plants can compete extensively with native plant species too, resulting in native resource reduction and even leading to pollinator population decline.
Monarch eggs on Swamp Milkweed (Asclepias incarnate) in a home garden. Taken by Laura Durenberger-Grunow.
Helpful resources for gardeners on the topic of native plants include the Homegrown National Park’s website, and one of Linehan’s favorite sources for native plant information – the Prairie Moon Nursery, a worker-owned, native plant nursery in Winona. Gardeners can peruse the nursery’s annual catalog to find information on host plants specific to certain butterflies.

Monarch caterpillars munch on the leaves of butterfly weed (Asclepias tuberosa), or sometimes referred to as butterfly milkweed, in a home garden. Photo by Laura Durenberger-Grunow.
“Butterflies of the Northwoods,” by Larry Weber, also offers comprehensive information on host plants for the various North Woods butterflies. Host plants serve as the required food source for their associated butterfly (and moth) caterpillars. For example, companions of interest to Cook County gardeners include: Pearly Everlastings to host the American Lady caterpillars (orange-black butterflies); Viburnums to host the Spring Azure caterpillars (tiny, blue butterflies); Hairy Beardtongue to support the Baltimore Checkerspot caterpillars (checkerboard-patterned butterflies); Smooth Blue Asters for the Northern Crescent caterpillars (black and orange butterflies); Common Blue Violet to sustain the Variegated Fritillary caterpillars; and Nettles for the red-banded Red Admirals.
“Without host plants, there won't be butterfly caterpillars in a garden. Sometimes caterpillars eat garden vegetable leaves, or the leaves of cultivar (non-native) flowers in a garden which irritates some gardeners...,” says Linehan. To combat this feeling of frustration, she suggests that gardeners look at planting native flowers as “a sharing process where we feed nature and ignore the holes in leaves, or better yet, rejoice when we see them.”
Monarch butterfly on Common Milkweed (Asclepias syriaca), submitted by Monarch Joint Venture staff member, Laura Lukens.
Lawns can also be included in gardeners’ overall plans to beautify on behalf of butterflies. The Lawns to Legumes program offers planting guides, training, and individual support grants for native plant installations in residential lawns for the benefit of pollinators like butterflies. Whether it is in the lawn or within a more formal garden area, gardeners should consider plant needs before making selections for their specific sites. “The trick is to meet the plants' needs or preferences: sun, part-sun, or shade? Wet, medium, or dry soil? Which planting zone?” says Linehan.
It can sometimes be tricky planting to support specific species in our area given the various Department of Agriculture gardening zones that are present throughout Cook County. The USDA Plant Hardiness Zone Map website can be an invaluable resource for gardeners. Site users can zoom in on a specific area within a zip code to determine the most appropriate zone for a particular location.

Many types of pollinators benefit from native plants. Photo taken by Laura Durenberger-Grunow.
Linehan offers an additional tip for Cook County gardeners to help them navigate this issue of varying zones. The Prairie Moon Nursery's website shares plant species-specific requirements and range maps. “As our climate changes, some natives may die out, or gradually migrate north to adapt. Already our planting zone numbers are changing...Plant sources will hopefully change their labels to accommodate these changes,” says Linehan.
Precipitation variability connected to climate change is one potential challenge for butterfly populations to overcome. Although Cook County has moved out of its most recent drought (according to the Minnesota Department of Natural Resources Drought Conditions website), spring drought conditions across the southern U.S. Monarch migratory pathway could impact population numbers here in the Midwest. “Drought can impact nectar resources, which are necessary to fuel migration. The overwintering colonies in Mexico were critically low this year, so the loss of a fuel source due to drought could be an added stressor as they move north and start to breed. Summer populations of eastern monarchs are primarily driven by the conditions in the southern U.S., where the first generation of monarchs is produced after arriving from their overwintering grounds in Mexico,” the Team members say. At the same time, our summers have some impact on monarch breeding populations, but “to a lesser degree than spring weather in the southern U.S”. The extent to which winter precipitation conditions in the Midwest impact Monarch populations has not been studied directly.
What we do know is that native plants have fewer water demands. In periods of drought, they may be a better choice from both a butterfly food source reliability point of view and a water conservation perspective. Beyond that, some butterflies like to "puddle" -- gathering at wet-dirt areas so they can get moisture. When it is appropriate given any water-conservation necessities, gardeners may want to put a bit of water on bare soil for those butterflies during dry spells, according to Linehan.
Red Admiral sunning on a rock. Photo taken by Jennifer Janasie.
Considering butterfly needs while planning and maintaining a home garden can be rewarding for gardeners as they witness the beautiful benefits of their labor. Gardeners will typically see Monarchs and Canadian Tiger Swallowtails begin to appear in the County sometime in June. Gardeners can later experience the wonder of finding the next generation of Monarch butterflies -- on their Milkweed host plants as caterpillars -- beginning in July. Find a Milkweed planting guide on the Monarch Watch’s Growing Milkweeds website, and help to support Monarch populations and the marvelous Monarch migration!
Remember to practice patience with the gardening process. “The most effective butterfly gardens are messy like nature, and require up-front plant selection, planning, and maintenance; but three years out, they begin to take care of themselves…and so they are less work for us. This is great if we have day jobs or are senior citizens with not as much mobility or energy,” says Linehan. Happy butterfly gardening!