A Monarch butterfly slowly opens and closes its black-and-orange wings while resting in the hand of June Bernard.
“Once you raise a Monarch from egg to a butterfly, you’re just hooked for life,” she said.
The 60-year-old Hampton woman has been fascinated with Monarchs since childhood. When she was in elementary school, she read about a Monarch tagging program in the Weekly Reader, a classroom magazine.
“When I was a kid, I searched for Monarchs to tag,” she said with a smile.
She works as an education specialist at the Pittsburgh Zoo and PPG Aquarium, where she has been working hard to spread the word about declining populations of Monarchs for more than a decade.
Studies in the Mexican forests where the butterfly spends winters show a sharp decline in population, especially over the last three years. This year, the butterfly covered only 1.65 acres of woodlands compared with 2.94 acres last year, according to Monarch Watch. The species covered almost 51.81 acres at its peak in 1996.
There are many reasons for the troubling statistics, Mrs. Bernard said, including habitat destruction in Mexico and severe weather conditions that have affected the butterfly’s favorite plants. Genetically modified crops, which can resist the herbicide Roundup, have also been an issue. Spraying does not affect GMOs but it kills weeds such as milkweed, which is the butterfly’s host plant.
In spring, Monarchs make a spectacular migration from Mexico to North America and return in the fall. On both journeys, they need host plants and nectar plants to feed on. Mrs. Bernard said we should start seeing Monarchs in June and that they will become more prolific during the summer as other generations are born.
Her advice to gardeners is simple: Plant milkweed everywhere. She has followed her own advice by filling just about every bed in and around the zoo with milkweed. There are four major types:
Tropical milkweed (Asclepias curassavica) — Grown as an annual here, it’s planted toward the end of May and succumbs to frost at the end of the season. The tender leaves make a great food source for the larvae and the flowers provide nectar for the adults. It’s one of Mrs. Bernard’s favorite plants for this purpose.
Swamp milkweed (A. incarnata) — a perennial plant that will come back each year. It does like wet soil but will also grow in average garden soil despite its name. The pink blooms are beautiful and fragrant, too.
Common milkweed (A. syriaca) — Also perennial, it spreads through underground runners and will thrive in full sun and average to poor soil. The flowers are purplish with a sweet aroma.
Butterfly weed (A. tuberosa) is shorter than the other two perennials with deep orange flowers that appear in summer.
Although Mrs. Bernard grows all four, she has focused on establishing common milkweed because it’s the toughest and most prolific of the group.
“All you need is one plant,” she said. “It can be an inch out of the ground and that Monarch will find it and lay eggs on it.”
She gives away seeds and seedlings to just about anyone who shows interest in helping the butterfly. She hopes gardeners can be one of the answers in reestablishing Monarch populations.
Growing common milkweed plant from seed or transplant can be a challenge, said Roxanne Swann, 43, coordinator of the Audubon Center for Native Plants at Beechwood Farms in Fox Chapel. The seeds have a hard coating and germinate better after stratification. That happens naturally when the seeds lie on the ground through a winter. Freezing and thawing cracks the seed coat and allows moisture to enter. When the conditions are right, the seed sprouts.
There are many predators for the seeds and seedlings. Insects, mammals and other things feast on both. At the Audubon greenhouse, seedlings are covered with screening to stop pests from devouring the plants.
Through Audubon’s Milkweed for Monarchs program, gardeners can pick up free seeds at the Audubon Nature Store. One of the easiest ways to grow them is to mimic nature. Fill a flat with moist planting mix in the fall and scatter the seeds on top. Keep them moist and store the flat outdoors for the winter, being sure to protect them with some type of screening.
“They need light to germinate. I always recommend planting a lot more seed than you expect to get plants from,” Mrs. Swann said.
They can be planted without the cold treatment, but germination rates aren’t as high.
Gardeners can also buy plants at the Audubon Center.
“Common milkweed grows very easy once established, but transplanting is difficult because it has a long tap root,” she said.
When talking about strategies to help the monarch, Mrs. Swann agrees herbicides are problematic. But so our other chemicals.
“Eliminate or reduce the use of pesticides. They are killing the caterpillars and destroying the host plant,” she said.
Miriam Goldberger, author of “Taming Wildflowers” (St. Lynn’s Press, $18.95) and president of Wildflower Farms, supports growing all four milkweeds. She said gardeners should also think about growing pollinator plants to help with the migration. These plants, most of which bloom later in the season, enable the butterfly to fuel up before and during the long journey.
Ms. Goldberger, 60, has three plants in mind — goldenrod, liatris and asters.
Showy goldenrod (Solidago speciosa) is one of her all-time favorites. “It’s beautiful, clump-forming (and) extraordinarily polite. It has beautiful majestic strong spikes of yellow and it’s super late-blooming.”
Since it’s one of the last plants to bloom, it provides crucial food for Monarchs as they wind their way south. And it’s not to blame for allergies, she said. “It’s really all about ragweed that bloom at the same time. The goldenrod gets blamed.”
Liatris, also known as blazing star, blooms in July and August. Any of the cultivars will work, but Ms. Goldberger likes meadow (Liatris ligulistylis), prairie (L. pycnostachya) and rough blazing star (L. aspera). “These are essential nectar support systems for the Monarch and lot of other beneficial insects,” she said.
When Monarchs were plentiful, they would cover meadow blazing star. Ms. Goldberger said biologists should study the plant to figure out what it is that attracts them to the flower. “The meadow blazing star is a Monarch plant supreme.”
Asters that attract the butterfly include sky blue (Aster oolentangiensis), New York (Symphyotrichum novi-belgii) and white (S. ericoides). New England aster (S. novae-angliae) might be Ms. Goldberger’s favorite.
“It’s great because it is so versatile. It will grow in sandy soil. It will grow in clay soil. It will even tolerate a little shade,” she said.
Just because some of these plants have “weed” in their name, don’t call them ugly.
“They are extraordinarily garden-worthy plants,” Ms. Goldberger said. “They are very elegant, long-blooming. They also happen to make great cut flowers.”
■ June Bernard teaches a monarch tagging class each fall at the Pittsburgh Zoo. Information: (412)-665-3640 or www.pittsburghzoo.org
■ The Audubon Center for Native Plants and Audubon Nature Store at Beechwood Farms Nature Reserve are at 614 Dorseyville Road, Fox Chapel (15238). Information: (412)-963-6100 or www.aswp.org
■ Miriam Goldberger can be contacted at www.tamingwildflowers.com or www.wildflowerfarm.com.
Doug Oster: firstname.lastname@example.org or 412-779-5861. Visit his garden blog at www.post-gazette.com/gardeningwithdoug. Twitter: @dougoster1.