Rules of attraction

Keen on butterflies? Curator from Concord has some advice

Bob Greene is curator of the Butterfly Garden at the Museum of Science, where visitors often ask about at-home gardens. (Globe Staff Photo / Pat Greenhouse)

Five days a week, Concord resident Bob Greene guides nature lovers through tropical 80-degree temperatures, pointing out exotic butterflies and plants typical of the Amazon rain forest. He is relaxed and cheerful despite the humidity, fielding questions and offering butterfly-viewing advice.

And he does so in sight of the Charles River and Boston's skyline.

Greene, 56, is curator of the Museum of Science's Butterfly Garden, a complex ecosystem of flora and from 30 to 50 varieties of butterflies, housed in a 1,200-square-foot glass conservatory perched above the river.

While many of the plants and butterfly pupae at the museum are shipped from Florida, Greene has been sharing some well-received advice with visitors: You can set up something similar in your own backyard.

"Even though this is a fairly exotic butterfly garden, you can create one out of what we have here," he said on a recent Tuesday afternoon as mothers and teenagers watched the museum's 200 or so butterflies flutter about their heads or pause to feed.

"We have a lot of beautiful butterflies in New England . . . Baltimore checkerspots, red-spotted purples, spicebush swallowtails," he said.

About 40 to 50 species of large butterflies are visible in Massachusetts, although there are varying estimates that up to 100 varieties may be native to New England, according to Greene.

Attracting butterflies, however, takes a bit of planning and proximity - the most important piece of the equation is "being near undeveloped woods and fields," Greene said.

If the location is right, the garden will require both host plants, where a caterpillar feeds in order to form a chrysalis, and nectar plants for the adult butterflies. Host plants common in the state include wild cherry and sassafras, while many flowers already popular in home gardens, such as black-eyed Susan, marigold, and zinnia, can serve as sources of nectar.

Another flower common in backyards is buddleia, a plant with cone-shaped flowers, varieties of which come in an array of colors. The plant is so attractive to butterflies that it's known as the butterfly bush.

"I've seen a lot of butterflies on these plants when I walked around Lincoln," said Greene, who lived in the town for 15 years before moving to Concord last year.

The fire-escape landing off Greene's Concord apartment isn't large enough to accommodate an at-home garden, although his career as a horticulturist has roots in a similar endeavor, he said.

Growing up in New Hampton, N.H., a small town at the foot of the White Mountains, Greene would collect unusual plants, including Jack in the pulpit and Solomon's seal, from the forest and replant them in a small plot that bordered a pond near his home.

Greene honed his horticulture knowledge at the University of New Hampshire in Derry, where he earned his degree and worked in the greenhouses and farms, and the Arnold Arboretum prior to joining the museum staff. Before the Butterfly Garden opened in 2005, Greene worked in the sun lab, where he was essentially given autonomy to design plant-biology exhibits and experiments.

The position has also provided travel opportunities, including exploring Venezuelan stretches of the Amazon Basin, and, more recently, learning about butterfly farming in Costa Rica from former cattle farmers who now raise the insects.

Many species the museum orders are native to that region of the world, which is why the Butterfly Garden is equipped with a heating and cooling system and weather station intended to keep temperature and humidity at a steady 80 degrees and 80 percent, respectively.

The life span of butterflies is so short - only a week to 10 days - that each week the museum receives shipments of 450 pupae from Florida, which continue to grow before being released into the Butterfly Garden, said Lea Morgan, the butterfly manager.

Among the crowds that pass through the exhibit, and nearly reach the 800 daily-visitor limit on weekends, "How do I do this myself?" is becoming a more common question, Morgan said.

William Benner, a Whatley resident and the president of the Massachusetts Butterfly Club, has also seen a sharp rise in the number of locals testing their green thumb with the purpose of attracting the colorful insects. He attributes the interest to a number of factors, he said.

"I think gardeners are starting to use native plants, use less watering, and less pesticides. Butterflies and hummingbirds are part of that" because of the beneficial insects they attract that can replace pesticides, Benner said. He's spotted about 50 varieties in his garden, which includes bee balm, composites, and milkweed, but mainly attributes that number to his rural surroundings in the western region of the state.