An interesting story by Joel Achenbach in today’s Washington Post is, on its face, about how the price of potting soil has soared in the past year due to the high cost of the fossil fuels used to manufacture, package, and ship the stuff. But read between the lines and the story is really about how a once humble material has been transformed into an upmarket mixture of largely unnecessary components from across the continent and around the globe — and about how gardening (or at least the kind practiced by many Americans), an activity by definition assumed to be “green,” is anything but.

Bob LaGasse, who represents soil and mulch manufacturers as executive director of the Mulch and Soil Council, explains that consumers demand these high-priced designer mixtures, which a South Carolina-based producer calls “potting soil on steroids.” (Bob LaGasse also happens to be executive director of the Garden Writers Association, representing the people who recommend potting soils and other horticultural products to consumers.) 

It’s virtually impossible these days to find a bag of potting soil that isn’t loaded with synthetic fertilizer. Nitrogen fertilizer, as David Wolfe, professor of plant and soil ecology at Cornell University, has pointed out, is the typical gardener’s biggest contribution to global warming. The manufacture of synthetic fertilizer is extremely energy intensive. And the use of nitrogen fertilizers (whether synthetic or organic) releases nitrous oxide gas, which in Wolfe’s words “has 300 times more global warming potential per molecule than carbon dioxide.” Yet American gardeners have been hoodwinked into believing that applying fertilizer to their plants, whether in containers or in the ground, is as fundamental as brushing their teeth.

In addition to organic matter, from composted clam shells to pine bark, which could just as easily come from local sources but is often shipped from far away, the typical bag of potting soil is also likely to contain perlite transported from the Greek island of Milos and coconut coir from Vietnam, if not peat moss “vacuum-harvested” from Canadian bogs. Then the concoction is packaged in plastic bags, which are piled up and shrink-wrapped on wooden pallets for shipping to nurseries and superstores. In short, the amount of embodied energy and greenhouse gases associated with a bag of potting mix is mind boggling.

All for a few petunia plants likely to end up in a dump after the first frost.

KQED radio has produced an interesting follow-up to the recent Plos One paper predicting that climate change will have a dire impact on redwoods and other plants that are endemic to California, America’s biodiversity hotspot — plants found nowhere else in the world. (My blog on the paper is here.) A KQED reporter interviews the authors and finds they’re even more pessimistic than they were when they wrote the paper. One sobering prediction: Most of California’s endemic plants will die if global warming continues at its present pace. At the end of the century, redwoods could still be growing in California because adult trees are so long-lived. But since no seedlings will be able to survive, these adults will be the last redwoods on earth, a forest of the “living dead.”

On the KQED website you’ll also find an interesting slide show based on the radio interview.

How will America’s biodiversity hotspot — the state of California — fare as the climate changes? Not great, according to a new paper in the peer-reviewed online journal PLoS One. Its findings have implications for plant conservation that are guaranteed to raise a few eyebrows. 

The paper was the buzz among botanists at the annual conference of the American Public Garden Association in Pasadena a couple of weeks ago. California’s diverse and distinctive flora faces a potential “collapse,” David Ackerly, an ecologist at UC Berkeley and the senior author of the paper, told the LA Times. “As the climate changes, many of these plants will have no place to go.” 

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It’s time to ditch, once and for all, the notion that plants are the dumb blondes of the biosphere. The typical suburban or city dweller sees plants as domestic accessories, with all the awareness of an Eames molded plywood chair. Even plant lovers tend to see them as horticultural eye candy, flaunting their pretty flower heads solely for our pleasure.

Set aside for a moment the fact that plants are capable of converting sunlight into food, or that some canny orchids can produce blooms that look so much like female bees that they’re magnets for the lovesick males who unintentionally pollinate the plants while attempting to copulate with their flowers. To me, this has always been evidence that plants are really smart.

Now scientists have demonstrated that some species can recognize members of their own family. In the British journal Biology Letters, plant ecologist Susan A. Dudley and colleague Amanda File set off a bit of a ruckus in the rarefied world of plant biology by describing an experiment in which they planted the Great Lakes sea rocket, Cakile edentula var. lacustris, in pots. Turns out there was a lot less competition when siblings shared the same container than when groups of strangers grew in a common pot — a feat of altruism members of our own species are not always capable of pulling off.

In fact, there’s so much new data on plant intelligence, including abilities like sensing and, yes, even learning and remembering, that scientists are now arguing about whether plants can be said to have nervous systems, if not brains. A scientific group called the Society for Plant Neurobiology was recently established to provide a venue for biologists interested in exploring, in their words, “complex plant behavior.” This prompted a backlash by three dozen exasperated scientists who published an article, “Plant Neurobioloogy: No Brain, No Gain?”, that took members of the new society to task for discussing the possibility that plants have neurons, synapses, and some vegetable equivalent of a brain, long considered the province of animals exclusively. Eric D. Brenner of The New York Botanical Garden, along with four other scientists, countered, “No one proposes that we literally look for a walnut-shaped little brain in the root or shoot tip.” But, they insisted, we should be open to the possibility that plants have their own sort of nervous system.

To keep abreast of the latest on plants as intelligent life forms, see the Society for Plant Neurobiology’s peer-reviewed journal, Plant Signaling & Behavior.

Well, after years of writing about bee watching, I’m now an official Bee Watcher. Twice a month, from spring through fall, I’ll be observing which bee species visit six native wildflowers I’ve planted on the roof of my Manhattan apartment building: common sunflower, woodland sunflower, mountain mint, milkweed, beebalm and goldenrod. I’m part of a New York City citizen science program that hopes volunteers like me can help researchers understand the challenges facing these essential pollinators, among them parasitic wasps and the mysterious Colony Collapse Disorder, which continued to decimate managed honeybee hives over the winter. There has been a lot of focus on honeybees of late, but surprisingly little is known about native bee species. Although they are also believed to be declining, there is little hard data to back this up, because most museum bee collections were made before World War II.

Being a Bee Watcher has its advantages. I’ve gotten free seeds and plants, and I’ve even learned a few things – for example, that North America has a very rich bee fauna, even relative to the tropics. This now includes 26 known introduced bee species in the U.S. and probably more – some of which are potential pests. And who knew that although butterflies and moths (except for migrants) tend to be sparse in urban habitats like mine, bees apparently take much better to city living?

The New York City Bee Watcher program is an outgrowth of the nationwide Great Sunflower Project, which is looking for volunteers. Which means you can be a bee watcher, too.  

A paper in the journal New Phytologist has truffle aficionados in a panic. Written by Claude Murat from the Dipartimento di Biologia Vegetale dell’Università di Torino and his colleagues, it documents the recent discovery of the aggressive Chinese black truffle, Tuber indicum, at an Italian truffle plantation. “We dread that T. indicum will spread all over Europe and crowd out T. melanosporum and perhaps other truffle species,” Murat told Science News. Lovers of the fungal lumps, underground reproductive structures that fetch astronomical prices in gourmet markets, turn up their noses at the Chinese species, considered much less flavorful and aromatic than European natives like the Périgord black truffle, T. melanosporum, and the even more precious Piedmont white truffle, T. magnatum. The record price of a single white truffle, $330,000, was set in December 2007, for a 3.3-pound specimen unearthed near Pisa by Luciano Savini and his dog Rocco. 

“The vegetable kingdom in Mars, instead of having green for a dominant colour, is of a vivid blood-red tint,” wrote H.G. Wells in War of the Worlds a century ago, when astronomers were trying to account for the planet’s color.

He may have been on to something, though not on that particular planet. Today, scientists searching for extraterrestrial life believe plants on other worlds might not be green. Their color would depend mainly on the type of star supplying the light used in photosynthesis. Plants on Earth are green because our sun is a relatively hot F-type star and chlorophyll is the appropriate photosynthetic pigment. But, as Scientific American reports, plants on planets orbiting feeble red dwarfs, the most abundant type of star in the Milky Way, might need to be black to absorb all the available light. On the other hand, plants growing in the light of a supergiant F-type sun might be shiny blue to survive its scorching rays. Don’t miss the fantastic artist’s renderings of these and other alien plants in the accompanying slide show.

With all the brouhaha about Bitter-gate, lapel pins, and polygamists in Texas, you may have missed the marvelous news that Swedish scientist Leif Kullman has discovered the world’s oldest recorded tree so far. It’s not, as was once believed, Methuselah, the 4,700-year-old bristlecone pine living in California’s Inyo National Forest. It’s a 9,550-year-old Norway spruce inhabiting a Swedish mountaintop. Kinda spindly looking but, hey, if we’d been around for almost ten millennia we wouldn’t be nearly as cute.

And now, another reason why air pollution is bad. It not only wrecks our lungs but also destroys flower fragrance. According to a new study, the scent molecules produced by blossoms bond quickly with ozone and other pollutants, producing chemically altered aromas that no longer smell like flowers. This, according to the researchers, could at least partially explain why wild populations of pollinators, especially bees, are declining in some areas, including California.