How to attract butterflies to your garden
Everyone loves butterflies because they're beautiful but they're also great pollinators.
Pollination is essential to the successful reproduction of more than 90 percent of the 250,000 flowering plant species now in existence. More than 100,000 varieties of insects, including bees, butterflies, moths and beetles, serve as pollinators. Pollinators also include at least 1,035 species of vertebrates, including birds and bats.
Pollinators are a "keystone" species, meaning, they are species on which the existence of a large number of other species depends. They are needed for their vital role for more than 150 food crops here in the U.S., as well as other valuable resources including medicine.
Unfortunately, research continues to verify the decline of the many pollinator species so important to the food sources and ecosystems on which we depend.
Want to help reverse the decline of butterflies in our communities and urban areas? There are simple things can we can do in our local landscapes and gardens to help provide them with food and habitat. These actions will also benefit bees, moths and hummingbirds. Taking time out for a little garden planning is a first step.
Prepare the site
Selecting a sunny location, remove as much lawn area as you feel comfortable removing (suggestion: try pushing your comfort level). Next, remove unwanted invasive plants like ivy and scotch broom, taking care to retain noninvasive species of thistle and dandelion. Make sure your yard provides at least partial sunshine for nectar plants butterflies also need sun for warming.
Before planting, experiment with the gardens shape by outlining the boundaries with your garden hose. Try different shapes, and amend the soil if needed. You'll want to strategically place shorter plants in front of taller ones, providing easy access and shelter for butterflies that frequent your yard. Note: if you currently have a small yard or live in an apartment or condo, you can create a nice container garden with fuchsias, sweet alyssum, dianthus, lavender and other plants suitable for pollinators.
Create a resting spot and water source
A log or large rock in a sunny location will provide a good place for butterflies to perch and rest. Butterflies also require moist soil or a shallow puddle. A slow-dripping faucet or water feature near a water-loving plant works well. You can also dig out 2 or 3 inches of soil about 24 inches wide in a frequently watered area to provide water.
Plant choices: food for caterpillars and butterflies
You'll want to start by figuring out which plants provide nectar for adult butterflies, and which will feed caterpillars. Choose several from each category and then evaluate your landscape or garden for best placement. In this way, your yard will provide for the entire butterfly life cycle.
Goldenrod (Solidago canadensis)
Goldenrod grows from 1 1/2 to 5 feet tall and features numerous lance-shaped leaves that contrast nicely with its yellow flowers. Give it full sun to partial shade, and trim it back each year.
Some species spread faster than others, which may or may not be to your liking. Inquire about species specifics at your local native plant nursery.
Showy milkweed (Asclepias speciosa)
The larval food plant for monarch butterflies, milkweed is most easily propagated by seed sewn outdoors after frost. Pretty, brightly-colored orange or yellow flower clusters are an attractive feature of this 1- to 3-foot-tall perennial plant, which favors dry sand or gravel soil.
Cow parsnip (Heracleum maximum)
These tall herbs have flat-topped or rounded white flower umbels characteristic of the carrot family, and are used by the Anise swallowtail.
Douglas' aster (Aster subspicatus)
A long-lasting display of bright lavender flowers from mid-summer well into fall will attract butterflies for its nectar. These flowers also brighten up the yard and landscape. Douglas' aster features many flowers per stalk, and grows to about 2 1/2 feet tall. It prefers slightly moist conditions, but can also thrive without irrigation. Starts easily from seed.
Hall's aster (Aster hallii) is somewhat smaller, and has similar growing requirements.
Western red columbine (Aquilegia formosa)
This common, attractive wildflower is native to North America, providing nectar for Western tiger swallowtail. Columbines thrive in various soil types and a range of light exposures from full-sun to part-shade, and are easy to find at most good nurseries.
Tiger lily (Lilium columbianum)
A nectar source for Western tiger swallowtail, these beauties prefer part sun and shade. Amend soil with mulch, leaves or peat moss. Plant the bulb about 3 inches deep with a small stone or wood chip beneath it to prevent the bulb from growing deeper.
Pearly everlasting (Anaphalis margaritacea)
This attractive native has gray, silvery leaves and stems. They bloom most of the summer with clusters of yellow and white flowers. In the fall, you can hang the cut flowers upside down to dry and use in floral arrangements.
Pearly everlasting is used by American lady butterfly caterpillars as a host plant, and is drought-tolerant. They also provide nectar for a variety of butterflies.
Douglas wallflower (Erysimum capitatum)
This pretty plant, a biennial member of the mustard family, is a host plant for Sara Orange Tip butterflies. Flowers have egg-shaped petals and are bright yellow to deep orange or red. Douglas wallflower prefers full sun to light shade, is low-maintenance and is drought-tolerant.
This popular perennial native is a legume and features flowers in whorls on a pike that are usually blue or purple, its a host plant for Gray Hairstreak butterflies. Lupine is fairly easy to grow from seed sown in the early spring in full sun. (Fender's blue butterfly, an endangered species, is host-specific on Kincaid's lupine).
These plants are a cheery sight, lasting from late spring through early summer. They feature tall stems of delicate hollyhock-like flowers, white to rosy-pink, and are actively visited by both bees and butterflies including the Gray Hairstreak butterfly.
Remember to include a generous portion of native grasses in your butterfly garden. California oat grass, Roemer's fescue and California fescue are all excellent bunchgrass choices for butterflies, including skippers and the common wood-nymph.
Willows (Salix scouleriana) are host to Western tiger swallowtail caterpillars, as well as mourning mloak and Lorquin's admiral butterflies. North America has approximately 90 different types of willow; generally, leaves are narrow and pointed. Be sure the willow(s) you buy are an upland variety (sourced from uplands you can ask at the nursery).
While we're on the subject of trees helpful to butterflies, you might also consider Black cottonwood or a locally-sourced quaking aspen. Both are often frequented by Lorquin's admiral, Western tiger swallowtail, and the mourning cloak butterfly.
Snowberry (Symphoricarpos albus) is a deciduous shrub with small, white, greenish-pink to white flowers. Plant them to assist the Chalcedon (variable) checkerspot butterfly, as well as for their appeal to a variety of birds and wildlife.
Another good shrub choice is Pacific serviceberry, used by Lorquins admiral, brown elfin, and Pale swallowtail butterflies. Ocean spray and ceanothus are other excellent choices.
Have your garden certified by the North American Butterfly Association
The North American Butterfly Association offers a certification program to encourage landscaping with butterfly-friendly plants. Three or more plants that supply food for caterpillars, nectar-supplying plants for butterflies, a water source and a location providing at least half a day's sunshine are the basic requirements.
Once certified, you're eligible to purchase a weatherproof Garden Certification sign for your yard or garden.
For more information: www.nababutterfly.com/cert_index.html.
Cynthia Orlando has a degree in forest management and is a certified arborist with the Oregon Department of Forestry in Salem.