There's pure magic in watching butterflies dance among the flowers. Those fluttering wings bring many of us back to childhood memories of our first encounters with the beauty of the natural world. As pollinators, butterflies are not only a captivating sight to behold — they're also instrumental in creating the rich and vibrant ecosystems all around us.
Butterflies may be some of the most charismatic and beautiful of all insects, yet their presence in our landscapes is a flashy reminder of these tiny visitors' importance to our ecosystems. There are over a million recorded species of insects, making up half of all life on earth. They perform an incredible range of vital jobs, from pollinating plants and spreading seeds to recycling nutrients and playing diverse roles in the food web. Insects uplift life on earth for birds, animals, and humans alike, yet their populations are steadily dropping. Butterflies are no exception: in the United States, butterfly populations have drastically decreased over the past 20 years. Even some of the best-known species like the Monarch butterfly appear to face an uncertain future.
Some good news: efforts to restore habitat have substantially helped insects like the threatened Fender's blue butterfly by replanting their singular host plant, Kincaid's lupine. By ensuring these rare Willamette Valley natives have the food and safe habitat they need, humans have helped restore a gorgeous member of our local ecosystem. This close-to-home example signals that there's hope for butterflies.
A visit from a butterfly is more than just a delight for humans — it also means that your garden is a safe haven and a working part of our wider ecosystem. As gardeners, we have a unique opportunity to support these important pollinators through our plant choices and landscaping practices. In this article, we're exploring ways to create habitat at home so that we and generations to come can all enjoy a world shared with butterflies.
The Plight of the Butterflies
While we usually see butterflies in our gardens and outdoors in nature, they live in the same rapidly-changing environment as we do. Our cities, farmland, and roads are all now part of butterflies' native ranges, creating novel risks that they have to adapt to in order to survive. According to Washington State University's Conservation Ecology Lab, the three main threats to butterflies are climate change, habitat loss, and pesticides.
Climate Change
Rising temperatures and intense weather events are throwing migratory butterflies like Monarchs for a loop. A winter heatwave is baffling to a monarch — the sudden rise in temperature can mimic the beginning of spring, triggering reproduction when these beloved beauties would usually stay dormant. Researchers think this is why winter monarch counts in California have varied so drastically in the last few decades — from millions in the 1980s to 300k in 2016 and just 1900 individuals in 2020. This number climbed back up to 200 - 300k before declining to less than ten thousand in the winter of 2024 - 25. At the same time, record numbers of caterpillars and breeding butterflies are often seen during these times instead, leading many to believe that there are more butterflies out there than we're actually counting. While the low numbers are definitely a sign of trouble for monarch butterflies, it's possible that the unpredictable weather is causing their overwintering behavior to change.
Habitat Loss
While some butterflies are generalists that enjoy a wide range of plants, other species' fates are tied to very specific host plants. For monarchs, this host is milkweed. For American painted lady butterflies, it's a native plant called pearly ever-lasting. For the Willamette Valley's own Fender's blue butterfly, their survival depends on the endangered Kincaid lupine — and this local pair have lost over 99% of their habitat over the past 200 years. The availability of these plants in the landscape makes it possible for their linked butterfly species to survive. As gardeners, we are intimately connected to this pattern: we have the power to expand butterflies' safe range by cultivating their host plants in our yards. This kind of action in nature preserves and on private property has helped the Fender's blue population rebound, offering an encouraging look at what's possible when humans work to help nature.
Pesticides
One of the major drivers of butterfly extinction is the pesticides (both insecticides and herbicides) used in agriculture, golf courses, and lawns. It's important to remember that butterflies are insects, so they (and other pollinators like bees and beetles) can be unintentionally harmed by insecticides used to treat unwanted pests. Scientists have found clear links between pesticide use and the decline of butterflies in the past few decades, so the best way to support butterfly habitat is to reduce pesticide use.
Collectively, all butterflies in the US have decreased by 22% from 2000 - 2020. That startling number is one that we may have noticed in our gardens, parks, and natural areas. Luckily, as we can see with the recovery of Fender's blue butterfly, there is hope for these ethereal pollinators when we make space for them in our shared landscape.
Gardening for Butterflies
Alongside the pressing reasons for caring about butterflies, their presence in our gardens is a treat to experience. When you're gardening for pollinators, there are few things as satisfying as watching your goals come full-circle as plants mature and begin to attract wildlife. The act of cultivating habitat brings you and your garden back into the ecosystem, which in turn helps pollinate your plants. The arrival of butterflies delivers beauty, wonder, and an intimate sense of accomplishment.
So, how do you attract butterflies? How can we garden with these graceful pollinators in mind?
Make Space for Butterflies in a Sunny Spot
When choosing an area of your garden to dedicate to butterflies, look for full-sun spots with a bit of protection from the wind (like the south side of a building or an area with trees or fences acting as a buffer). Many of our North American butterflies prefer full-sun plants and enjoy a safe location to warm their bodies in the sunshine as they rest.
Tip: Consider adding a shallow bird bath as a source of fresh water. Adding stones can help offer pollinators a safe spot to land and drink without falling into the water.
Minimize Pesticides
Butterflies are very sensitive to pesticides. Avoid systemic insecticides that persist in the plants' tissue, as well as herbicides that might harm "weedy" native host plants. If you must use an insecticide, we recommend carefully applying insecticidal soap or a biological agent like Bacillus thuringiensis (BT), which target harmful insects on contact but do not persist in the environment once dried.
Plant Native
Growing native host plants like milkweed, pearly ever-lasting, and nootka rose is an excellent way to create habitat for specific species of butterfly to enjoy. Generalists also appreciate native wildflowers in general. Below, we've included a large list of plants that support our native butterflies.
- Milkweed (Asclepias sp.)
- Goldenrod (Solidago sp.)
- Native Asters (Symphyotrichum sp.)
- Pearly ever-lasting (Anaphalis margaritacea)
- Wallflowers (Erysimum sp.)
- Tickseeds (Bidens sp.)
- Ceanothus sp.
- Thistles (Cirsium sp.)
- Stonecrops (Sedum sp.)
Choose Nectar-Rich Flowers
For a wide range of butterflies, non-native garden plants offer much-appreciated food sources and landing pads on their journeys through the landscape. Like above, we've curated some of our favorite ornamental plants that offer proven benefits for butterflies.
- Rudbeckias
- Hummingbird mint (Agastache sp.)
- Carnations (Dianthus sp.)
- Bee balm (Monarda sp.)
- Lantana sp.
- Veronica sp.
- Asters
Tips: "Double" flowers are attractive to us, but form outweighs function for our pollinators. Make sure to plant single-flowered varieties as well to offer pollen and nectar to butterflies.
Cultivate Habitat for Both Caterpillars and Adults
In addition to nectar-bearing flowers for adults, native trees and shrubs offer habitat for growing caterpillars. Remember — if you see bites taken out of your leaves, don't assume the worst. Minor insect damage also means that your garden is functioning as part of the ecosystem, offering "very hungry caterpillars" a source of nutrition to support them in their transformation into butterflies.
- For Monarchs: Showy Milkweed (Asclepias speciosa)
- For Swallowtails: Vine Maple (Acer circinatum), Redstem ceanothus (Ceanothus sanguineus)
- For Morning Cloaks: Pacific Willow (Salix lucida)
- For Spring Azure: Red-twig dogwood (Cornus sericea), American cranberrybush (Viburnum opulus)
- For American Painted Ladies: Pearly ever-lasting (Anaphalis margaritacea), Howard's Pussytoes (Antennaria howellii)
Butterflies for a Better World
Butterflies, colorful and charismatic, are some of the few insects that we actively welcome in our gardens. Seeing them offers a beautiful window into nature, showing us that our world is an interconnected web of life. At the same time, they can be a canary in the coal mine for the well-being of insects that we don't always give as much love. From butterflies and bees to beyond, our ecosystems rely upon these tiny neighbors — even when we don't immediately see the important work that they're doing. Just as human activity can cause harm to our environment, we can be active players in helping nature thrive alongside us.
Returning to the story of the Willamette Valley's endemic butterfly, the Fender's blue was thought to be extinct for much of the 20th century. As humans realized these resilient butterflies were still living among us and began paying closer attention to stewarding their habitat, they're now making a heartwarming comeback. With our help, we can only hope that other butterflies will rebound and continue to be captivating visitors in our gardens for generations to come.
On that note, growing a butterfly garden with your kids or grandkids is an amazing way to foster an early connection with nature. Even if you don't have the space to grow a huge pollinator garden, you can still be involved in the effort to support butterflies. Much of what we know about butterfly populations is driven by citizen science — programs where ordinary people observe and report butterfly sightings in their gardens and wider communities. If you'd like to get involved, take a look at the Xerces Society's list of Community Science programs around butterflies and other pollinators.
At Cornell Farm, we sell everything you need to get started on your butterfly gardening journey, from host plants to gentle garden products to even more free online resources for pollinator gardening. If you're growing a butterfly garden at home, tag us on social media @CornellFarm to share the inspiration with other Portland gardeners!
Sources:
Washington State University-led study reveals 20-year loss of butterfly populations across US (Oregon Public Broadcasting)
Monarch Butterflies in Western North America: A Holistic Review of Population Trends, Ecology, Stressors, Resilience and Adaptation (David C. James at WSU)
Fender's Blue Butterfly Species Profile (Xerces Society)
Biology and Conservation of At-Risk Butterflies — Washington State University
Western Monarch Butterfly Population Declines to Near Record Low (Xerces Society)
Native Plants for Attracting Butterflies (Native Plants PNW)
