By David Salman, Founder and Chief Horticulturalist for High Country Gardens
A butterfly garden can be a wonderful part of your landscape, and will make a meaningful difference by creating habitat for butterflies in all of their life stages. Anyone who loves growing plants and flowers can grow a butterfly garden. A garden that's good for butterflies is also good for other pollinators, such as bees and hummingbirds, who often share the same nectar plants and utilize the same habitat.
The Four Basic Elements of a Butterfly Garden
Flowers and food: Plant a mix of flowers that bloom from the start of spring through fall. Make sure to include food plants for caterpillars, such as Milkweed for monarch butterfly larvae.
Shelter: Leave some bare patches of ground or small brush piles (in unused corners of the yard). Leave herbaceous plants, such as grasses, standing over the winter to protect overwintering eggs and caterpillar pupae waiting to emerge.
Water: A mud puddle is ideal for butterflies, providing them with a source of water and salt/minerals. You can create one using a bird bath or submerged pie plate, and add sand, gravel and water.
A Safe, Pesticide-Free Environment: Don't use chemical insecticides (especially systemic ones). Use caution when applying organic pesticides and use herbicides only for a weed emergency.
Butterflies and moths have three stages in their life cycles before becoming the flying adult insects we recognize.
The mother butterfly lays eggs on preferred food plants.
The eggs hatch into caterpillars who feed on their food plants. These caterpillars grow to their full size before going dormant as a chrysalis (butterfly) or a cocoons (moth) in preparation for adulthood.
Then caterpillars go through metamorphosis and emerge as flying adults. Adults mate, lay eggs, feed and die, leaving behind the next generation.
Plant Both Caterpillar and Butterfly Food
Often the flowering plants that feed the adult moths and butterflies are different from the plants that feed caterpillars. For a butterfly garden, the gardener must plant both.
Most flowers that attract butterflies and moths will feed a wide range of species.
When it comes to feeding their caterpillars, butterflies and moths can either have a need for very specific food plants or have a taste for a wider range of plants. This depends on the species of each moth and butterfly as they will have different requirements.
'Prairie Gold' Butterfly Weed (Asclepias tuberosa) is a beautiful golden-yellow form of this popular native wildflower. This selection is grown from seed collected from a wild population in its Indiana habitat. Grow this special native cultivar to add unexpected color and an interesting conversation starter to your pollinator garden. A 2021 High Country Gardens Introduction.
Our Superstar Aster Collection is an easy solution for late summer to fall color. Native Asters are important late-season food sources for bees and butterflies, including Monarchs. Featuring five varieties of Asters for an array of colors and varying heights, this collection will refresh the garden with late season flowers, just as summer’s blooms begin to fade. Collection of 5 plants. (Symphyotrichum)
One of the first asters to bloom, Monch Frikart's Aster (Aster x frikartii Monch) flowers from mid-summer into fall, with lavender-purple petals surrounding golden-yellow centers. This easy to grow hybrid is mildew resistant. Once established, Asters are drought-tolerant, vigorous, long-lived perennials that provide an important source of and late-season food for pollinators.
Honeysong Pink New England Aster (Symphyotrichum novae-anglie) announces fall with an abundance of lovely pink, golden-centered flowers. Standing tall, it is a perfect solution for adding height to the back of the perennial border. A pollinator favorite, this easy to grow native cultivar will bloom from late summer well into fall, filling the garden with late season color and visiting pollinators.
It is important to not spray indiscriminately in your yard and kill caterpillars. Even organic formulations like BT (Bacillus thuringiensis) that you would spray to kill corn earworms (moth caterpillars), are broad spectrum and will kill all moth and butterfly caterpillars.
It's also essential NOT to use systemic chemical insecticides (absorbed through leaf tissue and distributed through all parts of the plants including flowers). Many of these formulations are Neonicotinoids. Systemically treated plants have toxic flowers which will poison the adult butterflies and moths!
And if you have tomatoes, you'll have "horn worms", the caterpillar of hawk moths. These are the hovering hummingbird-like moths that pollinate flowers at dusk like Evening Primrose (Oenothera) and Hummingbird Mint (Agastache). So plant an extra tomato plant or two and pick off the horn worms, don't spray, leaving some to mature into adults.
The Xerces Society is a nonprofit organization that protects wildlife through the conservation of invertebrates (insects) and their habitat. For over forty years, the Society has been at the forefront of invertebrate protection worldwide, harnessing the knowledge of scientists and the enthusiasm of citizens to implement conservation programs.
The society has just published an excellent new book: "Attracting Native Pollinators: Protecting North America’s Bees and Butterflies" which is available on their website: http://www.xerces.org.
It will give you a lot more specific information on what to plant regionally to support native butterfly populations in your garden and landscape.