The following was published as part of my regular “Growing Greener” column in Public Garden magazine, Vol. 24 No. 3 (2009). Public Garden is the flagship publication of the American Public Gardens Association. In “Growing Greener” I answer sustainability-related questions from public garden staff.

Q: There are so many different green roof systems. Are they all effective?

A: It’s easy for us plant enthusiasts to be seduced by the idea of verdant rooftops. Aesthetically, living roofs are a major improvement over typical asphalt or tar roofs, which are about as hospitable to humans and most other life forms as Death Valley on a mid-summer day. But before falling head over heels for green roofs it’s worth asking whether they really, as touted, help insulate buildings and thus save energy that would otherwise be consumed for heating or cooling, counteract the urban heat island effect, remove particulates from polluted air, detain and cleanse storm water, and more. (more…)

The following was published as part of my regular “Growing Greener” column in Public Garden magazine, Vol. 24 No. 1 (2009). Public Garden is the flagship publication of the American Public Gardens Association. In “Growing Greener” I answer sustainability-related questions from public garden staff.

Q: What is a green exhibit? How green does it have to be?

A: A green exhibit isn’t necessarily one that tells visitors how your garden is becoming more sustainable and how they can, too (though that’s a good idea!). Exhibits of all types and sizes can be beautiful expressions of sustainability. As for how green to go, you should make your exhibits as green as you can, and keep growing greener.

By now, most people in the public garden world are familiar with the LEED guidelines, performance benchmarks, and rating system for green buildings. The same basic guidelines can also be used for creating a green exhibit. (more…)

The following was published as part of my regular “Growing Greener” column in Public Garden magazine, Vol. 23 No. 3/4 (2008). Public Garden is the flagship publication of the American Public Gardens Association. In “Growing Greener” I answer sustainability-related questions from public garden staff.

Q: What is the Sustainable Sites Initiative, and how can public gardens use it?

A: In the past several years, the LEED^R program of the U.S. Green Building Council has become synonymous with sustainable design. The USGBC awards four levels of LEED certification for the design, construction, and operation of high-performance green buildings: Certified, Silver, Gold, and Platinum. This rating system has provided targets for public gardens and other institutions striving to go green.

One limitation of LEED, especially for public gardens, is that it currently is concerned primarily with buildings. It’s not surprising, then, that two public gardens, the Lady Bird Johnson Wildflower Center and the United States Botanic Garden, have teamed up with the American Society of Landscape Architects to produce the Sustainable Sites Initiative, the first program to develop guidelines and standards for sustainable landscapes. (more…)

The annual meeting of the American Public Gardens Association always charges my batteries. This year’s meeting in St. Louis was no exception. Among other things, it gave me the kick in the pants I’ve needed to actually post the “Growing Greener” columns I write for Public Garden magazine, APGA’s flagship publication. In each issue, I answer sustainability-related questions submitted by public garden staff. You can find my column on the carbon footprint of homegrown food here. I’ll be adding additional columns over the next few days.

Kudos to the Shangri La Botanical Gardens in Orange, Texas, whose new interpretive center has been chosen as one of the American Institute of Architects’ Top Ten Green Projects of 2009. The Orientation Center contains an exhibit hall, theater, interactive children’s garden, classroom and exhibition greenhouses, and a water demonstration garden that shows how plants filter pollution from water, as well as a café, garden store, volunteer center, and administrative spaces. There are also several “outbuildings,” including a Nature Discovery Lab and pavilion, outdoor classrooms, a bird blind, and a boat house, deep in a cypress swamp. You can find lots of information on the LEED Platinum facility, including photos, on the AIA website.

To celebrate meeting its target of collecting seed of 10 percent of the world’s plants—about 30,000 species—for storage in the Millennium Seed Bank as insurance against extinction, Royal Botanic Gardens, Kew is celebrating with the exhibit Banking on Life. The exhibit includes Rob Kesseler’s amazing electron micrographs of seeds and pollen. A slide show of some of these bizarre and beautiful structures is here.

The Millennium Seed Bank is the largest wild plant seed bank, with over a billion seeds collected from around the globe. The second phase of the program will aim to conserve an additional 15 percent of the world’s plant species by 2020. The estimated £100 million needed to accomplish this still need to be raised. Here’s how you can help.

As spring sweeps across the country, some public gardens are capturing the spectacle of blooms online. Anyone in need of a bluebonnet fix can check out the Lady Bird Johnson Wildflower Center’s Bluebonnet Cam, updated hourly. It’s too early to tell whether anyone will top Brooklyn Botanic Garden’s 2008 tour de force, a time-lapse video of 3,000 photos of its famous cherry tree collection—from the early buds to peak bloom—complete with original music.

I first saw the hemlock wooly adelgid in action about 15 years ago. Its telltale wooly white egg masses appeared on a few branches of three hemlock trees in my next-door neighbor’s yard in Park Slope, Brooklyn. Within three years the trees were dead. Since then the insect, which arrived in North America from Asia in the 1920s, has become a major scourge of eastern forests from Maine to Georgia. It is spreading rapidly into the oldest and largest hemlock stands in the Southern Appalachians, where some of the trees are 800 years old and more than 175 feet tall.

In fact, new research suggests the hemlock woolly adelgid is killing hemlock trees even faster than expected in the Southern Appalachians and most of the region’s hemlocks could be dead within the next decade. The hemlock plays a fundamental role in the ecology and hydrology of mountain habitats. Its thick, evergreen canopies help cool mountain streams that are home to trout. Many birds find shelter and places to nest in the hemlock’s evergreen boughs. In one study, 96 percent of all wood thrush nests found by surveyors were in hemlocks. Some warblers only nest in hemlocks.

Few of the growing number of U.S. native trees beset by pestilence have a federal task force devoted to their survival. The hemlock does. Among other things, the Hemlock Wooly Adelgid Action Team coordinates control efforts and runs a public education and outreach campaign. While homeowners can treat individual trees with horticultural oils or chemical pesticides, this isn’t practical for entire forests of afflicted trees. The most promising backwoods treatments found so far are two tiny nonnative beetles that dine voraciously on adelgids (and, scientists say, only adelgids). Tests in Connecticut and Virginia show that these beetles can reduce hemlock wooly adelgid populations by 47 to 87 percent in five months. The beetles have been released in selected areas throughout the Southern Appalachians.

Still, the scale of the hemlock wooly adelgid epidemic is so huge that scientists and public land managers won’t be able to contain it without the public’s help. Details on how you can monitor and treat trees on your own property and get involved in efforts to protect hemlocks in the wild are on the Hemlock Wooly Adelgid Action Team’s website.

Several of the world’s greatest public gardens are celebrating birthdays this year. The Royal Botanic Gardens, Kew in London turns 250. Missouri Botanical Garden, the oldest botanic garden in continuous operation in the U.S., is celebrating its 150th birthday; to help celebrate the occasion, the American Public Gardens Association is holding its annual meeting in St. Louis this summer. Meanwhile, the Singapore Botanic Gardens is also celebrating its (ready for the Word of the Day?) sesquicentennial.

You can find my somewhat quirky take on the history of botanic gardens here. 

Good news for public gardens, zoos, and other places where visitors engage in “informal learning” about science. (For those new to the jargon, informal in this context basically means outside the classroom.) According to a new report sponsored by the National Science Foundation, “there is abundant evidence that these experiences contribute to people’s knowledge and interest in science.” What’s more, “they may also support academic gains for young people from groups historically underrepresented in science,” like minorities and women.

The report has some useful recommendations for people who create exhibits and other informal science programs: The exhibits should be interactive and designed with specific learning goals in mind. They should encourage visitors to relate what they have learned to their prior experiences and interests, and when possible the exhibits should be rooted in scientific problems, ideas, and activities that are meaningful to their communities.

Professionals who evaluate informal science programs for a living will be pleased to hear that there are some useful ways to measure “outcomes” (more jargon, meaning  ways to assess how well people have learned the science lessons the exhibits are intended to teach). But, sorry, to learn what these are, you have to shell out the $42.26 for the report.

You’d think that studies paid for by our tax dollars would be available for free on the internet. But I guess that kind of learning is a bit too informal for the NSF.