The Great American Desert

[I wrote this piece a few years ago, but the History Channel's recent broadcast of Black Blizzard, along with Tim Egan's narrative and interviews with Dust Bowl survivors, makes it worth repeating.]


"When the native sod of the Great Plains was in place, it did not matter if people looked twice at a piece of ground. Wind blew twenty, thirty, forty miles an hour, as always. Droughts came and went. Prairie fires, many of them started deliberately by Indians or cowboys trying to scare nesters off, took a great gulp of grass in a few days. Hailstorms pounded the land. Blue northers froze it so hard it was like broken glass to walk on. Through all of the seasonal tempests, man was inconsequential. As long as the weave of grass was stitched to the land, the prairie would flourish in dry years and wet. The grass could look brown and dead, but beneath the surface, the roots held the soil in place; it was alive and dormant.
The short grass, buffalo and blue grama, had evolved as the perfect fit for the sandy loam of the arid zone. It could hold moisture a foot or more below ground level even during summer droughts, when hot winds robbed the surface of all water-bearing life. In turn, the grass nurtured pin-tailed grouse, prairie chickens, cranes, jackrabbits, snakes, and other creatures that got their water from foraging on the native turf. Through the driest years, the web of life held. When a farmer tore out the sod and then walked away, leaving the land naked, however, that barren patch posed a threat to neighbors. It could not revert to grass, because the roots were gone. It was empty, dead, and transient."

—Timothy Egan, The Worst Hard Time: The Untold Story of Those Who Survived the Great American Dust Bowl

Read this book.

Four Degrees of Separation

What a difference four degrees makes.

That's the difference in latitude between my office in Palo Alto, Calif. (37.4 degrees, just south of San Francisco) and my current vacation spot in Carlsbad, Calif. (33.1 degrees, just north of San Diego).

Up north, we can't grow Jacaranda mimosifolia very successfully due to our typically frosty and occasionally freezing winters. Down here, the tree's vibrant lavender blooms are pretty much ubiquitous this time of year.

Up north, our soil is heavily influenced by at least four local ancient volcanoes — mounts Diablo, Hamilton, Tamalpais and Sonoma — with a resultant fertility that made today's Silicon Valley the original "Valley of Heart's Delight." Down here, with the nearest volcanoes some 4–5 hours away, the local soils are much more estuarine, sandy and lacking the minerals and clays that nourish "exotic" plants.

Up north, Palo Alto averages about 15" of rain annually, contributing to a mostly foothill woodland native plant habitat bordering on evergreen forest. Down here, Carlsbad averages about 7" of rain annually, creating a predominantly coastal sage scrub community.

Up north, our average summertime high temperature is above 78° Fahrenheit. Down here, the average summertime high temp is just under 74°F. However, thanks to the famous San Francisco fog, at night we can drop 22°F — while closer to the equator, Carlsbad drops only 10°F.

Obviously there are pros and cons to each latitude, but you can see how just a few degrees of separation can significantly affect environments and lifestyles. Where would you rather live? And if prognostications of global warming expanding the equatorial zones are correct, and Palo Alto comes to resemble Carlsbad and Carlsbad comes to resemble Puerto Lobos, how would your lifestyle change?

Good Day, Mr. President

Now that Senator Obama is President Obama, I'll set down my champagne for a moment to briefly digest his environmental past and promises.

In 2006, Obama introduced the Healthy Places Act in Congress, an effort to create accountability by helping local governments assess health impacts of new projects. His website details his new administration's "comprehensive plan to invest in alternative and renewable energy, end our addiction to foreign oil, address the global climate crisis and create millions of new jobs." He also puts some focus on sustainable urban planning.

Grist.com last month set out a review of Obama's environmental policies. Most of these are centered around changes to U.S. energy policy, but the article also includes a few quotes from Obama interviews indicating that his religious faith plays an important role in his outlook on the environment, a fact confirmed in this AP article by Amy Lorentzen.

It's also instructive to read into Obama's picks for environmental and energy policymakers. These folks are not only luminaries in their fields, but clearly bring a bias toward research-based policy, from the reality of climate change (regardless of its origins) to the potential of renewable energy sources. I'm particularly optimistic that under new EPA Administrator Lisa Jackson, both forest and wetland wildlife habitats will be increased.

The ASLA has been optimistic as well that a change of administration will bring a change in priorities. Their site publishes a list of initiatives, as well as proposed angles on the economic stimulus package that will help the profession and the planet.

Our new President has the opportunity — obligation, even — to reform America's farm bill, a la Michael Pollan's recommendations. A couple of weeks after Pollan's letter, Obama was interviewed by TIME and indicated that he had not only read it, but also understood the costs of an agricultural system "built on cheap oil":

"There is no better potential driver that pervades all aspects of our economy than a new energy economy. I was just reading an article in the New York Times by Michael Pollan about food and the fact that our entire agricultural system is built on cheap oil. As a consequence, our agriculture sector actually is contributing more greenhouse gases than our transportation sector. And in the mean time, it's creating monocultures that are vulnerable to national security threats, are now vulnerable to sky-high food prices or crashes in food prices, huge swings in commodity prices, and are partly responsible for the explosion in our healthcare costs because they're contributing to type 2 diabetes, stroke and heart disease, obesity, all the things that are driving our huge explosion in healthcare costs. That's just one sector of the economy. You think about the same thing is true on transportation. The same thing is true on how we construct our buildings. The same is true across the board."

Obviously there are plenty of pressing issues that will demand President Obama's attention. Even though he has invited our participation to an unprecedented degree, I'm under no delusion that he can (or would) reform all our bad habits with the stroke of a pen. We have sky-high expectations, for sure, and there are plenty of voices more than willing to keep our new Ecologist-In-Chief in check. But I am encouraged that those of us who love our planet now have at least a fighting chance to see some redemption.

Today is a very good day, indeed.

Water in the Landscape

California is officially in a drought (although personally I suspect this is our normal climate and those other years were just extra wet). Some water districts have implemented mandatory rationing, while others are still able to request voluntary cutbacks… for now. But it behooves all of us to be conscious of our water use, and water-wise landscaping is an easy first step.

The Santa Clara Valley Water District has created a very nice booklet on landscape planning, from layout to planting and of course irrigation practices. Their site also offers a list of water-wise plants, not exhaustive but certainly robust enough for most of us. And, if you needed any more incentive, the district is offering a landscaping rebate of up to $1,000 to replace your thirsty turf lawn with more efficient plantings, or an irrigation rebate of up to $1,000 to install drip systems, rain sensors and other "smart" irrigation products.

The Association of Professional Landscape Designers also has issued guidelines to keep its members cognizant of practices that not only reduce irrigation needs, but also respect natural cycles by encouraging stormwater detention and holistic ecological planning. The American Society of Landscape Architects has also issued some pointers on conserving water as well as greening your home overall. And the California Landscape Contractors Association offers not only tips on how to "reduce your use," but also resources for finding certified water managers to install or optimize your low-water landscape.

The threat of a serious and prolonged drought is an abrupt wake-up call for all of us, and the options for adapting to it can be overwhelming. Start by speaking with your landscape professional — designer, architect, or contractor — and you'll get both reassurance and real solutions to save water and save money.

(Happy) Earth Day

Hooray. It's "Earth Day." One day, 24 hours, for us to be more aware and appreciative of the Earth's environment.

Woo hoo.

Never mind that the other 364 days of the year we're driving our SUV around town, alone and comfy in our captain's chair.

Or that we still leave the water running while we wash our hands with antibacterial soap.

Or that our salmon are now in as much trouble as our tuna.

I put honey in my tea today and was confronted by two unwelcome thoughts:

If this isn't "organic" honey, what crap pesticide residue am I drinking now?

When the bees go extinct, how will I put honey in my tea?

Across the street, the neighbor's sprinklers spray well beyond the curbside planting strip, flooding the gutter and soaking the cars parked there. Then the gardener fires up his gas-powered leaf blower, creating great clouds of dust and grass clippings and pollen that immediately adhere to the wet cars. I am not making this up.

It seems to me that we, as a society, have gone mad. We are pathological, behaving in ways that clearly harm others, if not directly ourselves. We are compulsive, unable or unwilling to modify our behaviors even when it's made clear that they are destructive. And we are delusional, somehow believing — despite overwhelming evidence to the contrary — that our actions either don't have consequences or will be mitigated by someone else.

It's been about two years since Al Gore's An Inconvenient Truth made us all wince just a little bit. And yet the troubles have been on people's lips for more than 15 years — I caught Batman Returns on TV over the weekend, and even in 1992 the Penguin referenced "global warming." I understand that sometimes Hollywood can seem out of touch, but major studio releases don't make their money referencing arcane phenomena advanced only by the intelligentsia.

I was going to write today about a few things we all can do to help our planet, our neighbors, our children. Little things, things you might actually do, like converting your lawn to low-water plantings, not like converting your SUV to biodiesel. But honestly, we've known we're in trouble for, let's conservatively say, a decade. What have you changed in that time? Have you converted your lawn to low-water plantings? Have you stopped buying products whose manufacture kills the environment? Do you recycle and/or compost most, if not all, of your waste?

If you have, great. I applaud you. Tell us all about it, if for no other reason than to help us sustain our delusion that someone somewhere is fixing the problem we're creating. But when my clients still demand lawns that no child will ever play on… when "my" contractors still install spray irrigation because drip is too difficult… when I myself still drive my SUV around town, solo… I think perhaps the problem is outpacing the fix.

So, seriously: what are we going to do about it?

Fall into Winter

Foliage-wise, this has been one of the best autumns I can remember. And now that all those lovely leaves are coming down to earth, we're reminded that winter is just around the corner (here it comes at about 10:08 pm Friday night).

The gorgeous displays of reds, oranges and golds is especially striking this year because [a] it's been a very cold and dry season, both of which stress trees into withdrawing their green chlorophyll earlier and more quickly (thereby revealing the natural anthocyanins and carotene colors), and [b] the lack of rain and wind has left those vibrant leaves on the trees longer. Now that the storms are arriving, we're getting more of what we're used to:

Autumn gardens are among my favorites, not only for their foliage colors but because of the way the winter light plays on details such as leaf margins and seed heads, such as the tall Miscanthus and Calamagrostis grass plumes that look splendid all golden and backlit. Other specimens, such as the coral-bark Japanese maple and the river birch, start showing some of their best assets that are hidden, or at least overshadowed, most of the year. But there's no denying that colorful foliage is the star of the season, especially when set against a backdrop of dark evergreens such as pines, redwoods or even magnolias. Some of my favorites include:

Pyrus calleryana (Callery Pear) — different varieties have different colors and forms

Ginkgo biloba (Maidenhair Tree) — venerable forest giant with clear yellow to gold color; leaves all seem to drop within a few days

Lagerstroemia hybrids (Crepe Myrtle) — a three-season star, with gorgeous winter bark and bright summer flowers to complement fiery autumn foliage

Viburnum cultivars — small to large shrubs with bright red to purple fall color

Hydrangea quercifolia (Oakleaf Hydrangea) — orange to red leaves even as the flower panicles hold on

Blueberry cultivars — yes, the edible blueberry bush will give an amazing fall show if you dare withhold water for a while

Ceratostigma plumbaginoides (Dwarf Plumbago) — Fast growing, shade tolerant ground cover colors bright crimson; a nice surprise at ground level

Vitis californica 'Rogers Red' (California Wild Grape) — A great choice to slipcover a garage or obliterate a fence within a few seasons, stops traffic when it turns wine red

As you're out and about over the next few days, I hope you'll make it a point to notice and appreciate the colors before they're brought back to earth by the rain and winds. If you see something particularly stunning, feel free to send it in. And if you have favorite autumn plants of your own, please share!

The drought is coming! The drought is coming!

Given that San Francisco's rainfall during the 2005-2006 season was about 157% of normal, it's a little weird to me that after one dry winter the PUC is raising the specter of voluntary or even mandatory water restrictions. Nevertheless, numbers don't lie (or do they?), so we better get thinking about how to reduce our water usage.

Which brings me back to the ultimate water hog, lawn. Brian of Mauby All Natural was kind enough to suggest he could "improve soil condition to a point where water use can drop by 75%." Brian's primary product seems to be compost tea, which is an excellent amendment and one whose regular use I regularly recommend for my clientele who are serious about improving the overall health of their soil. But turfgrass being turfgrass, I'm hard pressed to understand how it could thrive on 5,000 gallons of water a year instead of 20,000.

So what's better: spending 12,000 gallons (I'll give Brian partial credit) of our precious Sierra snowpack on irrigation each year, or tossing 750 square feet of plastic into the landfill each decade? I honestly don't know the answer. If you do, please share with the class.

The Reality of Sustainability

"Even when we are trying to aid the environment, we are not willing as individuals to leave the system that we know in our heart of hearts is the cause of our problems. "

and

"We’re willing to be generous in order to 'save the world' but not before we’ve insured our own survival in the reigning system."

So writes Curtis White in the current issue of Orion magazine. I take his point painfully well: I'm becoming increasingly aware of my unique position to "aid the environment," to design not just gardens but environments that help put things right rather than add to the problems. Yet I'm driving around in an SUV that gets 18 mpg. If estimates are correct, I've sent about 20,000 disposable diapers to the landfill so far (and counting). And I can't help it: I really think landscape lighting is an important element in your yard, even though it does increase your carbon footprint.

I would like to think I can help change the reigning, unsustainable, system. My job, unlike many others described by White's essay, probably has net environmental benefits. But I'm nowhere near being able to live sustainably in my own home, much less overhaul the lifestyles of my clientele who still believe they need massive lawns and impermeable paving everywhere.

I wish White would provide examples of people, companies or roles that he feels are breaking the system. But even so, the larger context of our society and culture places an unfortunate emphasis on "the convenience of money"; so the statement I feel most sympathetic with is White's closing:

"We are not ready. Not yet, at least."

Postscript 3/26/07: Alex Steffen writes a provocative piece on "strategic consumption":
You can be heroic in your efforts, but at the moment it's essentially impossible to live a North American consumer lifestyle and do no harm. You can buy only organic food, recycled products, and natural fibers and you won't get there. You can even trade your car for a hybrid, harvest your rainwater and only run your CFLs off your backyard wind turbine, and you still won't get there, both because the waste associated with consumerism is so massive and because the systems outside your direct control upon which you depend -- from your local roads to your nation's army to the design of the assembly lines used to build your car, rain barrel and windmill -- are still profoundly unsustainable. You quite literally cannot shop your way to a one-planet footprint. The best you can do is nudge the market in that direction.

Yeah. What he said.

It's Official

"Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice, and rising global mean sea level… Most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations."
—Intergovernmental Panel On Climate Change, Climate Change 2007: The Physical Science Basis

How Dry We Are

From San Francisco Chronicle writer Glen Martin:

This season's scant rainfall doesn't yet mean we're in a drought -- but it's starting to feel that way. San Francisco is on track to post its fifth-driest January since 1850.

So far, San Francisco has recorded only 0.65 inches of rain compared to a normal rainfall of 4.72 inches. … And California as a whole is just as parched. Most crucially, the Sierra snowpack -- which provides Californians with most of their drinking and irrigation water -- has only 45 to 60 percent of its normal water content, depending on location. And it's not improving.

"The snowpack is declining," said Dan Gudgel, a meteorologist with the National Weather Service. "Every day that goes by with no precipitation puts us further behind with less prospect of catching up."

That's because California typically gets most of its precipitation in January, February and March, Gudgel said. Worse, no significant storms are headed this way.

Martin goes on to note that, while comparisons to the reservoir-draining droughts of the 1980s and 1990s may be premature, "The state's population is much larger now and would be harder-hit by a severe drought."

I was struck just a couple of weeks ago by how low the Lexington Reservoir, near Los Gatos, still was; and couldn't help but wonder what a drought might do to my business. Would homeowners clamor for water-wise makeovers? Or sit on their hands while their pretty flowerbeds and lush lawns became withered and crisp? Should I be in the business of green lawn paint?

Mostly, though, I was reminded of the wisdom of designing with "unthirsty" plants and low-flow irrigation systems, and the necessity of educating my clientele that we are, after all, a Mediterranean climate—meaning the next drought has every right to manifest this year (no matter what El Niño says). Are you ready?

Global Freezing

Ahh, January, when citrus trees all over town suddenly sprout baby blankets and plastic tarps in (misguided) efforts to keep from freezing.

A covering simply draped over the plant won't protect the plant: the covering will quickly reach the same temperature as the ambient air (i.e. freezing) and in turn freeze whatever it's contacting (i.e. the plant). Propping the cover up a few inches above the foliage, on bamboo poles or broom handles or steel spears, will, on the other hand, create an insulating cushion of air between frost and plant. A string of holiday lights draped over the plants will further warm the plants.

It's more or less a rule of thumb that crops can be damaged when temperatures fall below 28 degrees for about five hours. This particular cold spell may in fact bring those conditions to Palo Alto; but in general, we just don't get that cold. Don't bother blanketing the babies until Wunderground is predicting 30°F or lower.

And finally, leaving those coverings in place all day may be just as bad as not having them on the coldest nights. Despite how cold it's been, we're also having daytime temps in the 50s and 60s. Which means that a plant left wrapped in plastic during these clear sunny days may, in fact, be sweltering! If you just can't bear taking the tarps off every morning and replacing them every evening, at least make sure there's a significant amount of open area near the ground for air to circulate.

There's no shortage of advice on protecting tender plants, so I'll leave that to others. I'll just end with this: much of California is, intrinsically, a desert, with hot arid summers and cold winters. If you're losing sleep worrying about your Brugmansia and cherimoya specimens, perhaps it's time to ask whether you might be in zone denial? Not that even the best among us aren't… but as the climate continues to remind us who's boss, we might want to start planting a little more appropriately.

The Great American Desert

"When the native sod of the Great Plains was in place, it did not matter if people looked twice at a piece of ground. Wind blew twenty, thirty, forty miles an hour, as always. Droughts came and went. Prairie fires, many of them started deliberately by Indians or cowboys trying to scare nesters off, took a great gulp of grass in a few days. Hailstorms pounded the land. Blue northers froze it so hard it was like broken glass to walk on. Through all of the seasonal tempests, man was inconsequential. As long as the weave of grass was stitched to the land, the prairie would flourish in dry years and wet. The grass could look brown and dead, but beneath the surface, the roots held the soil in place; it was alive and dormant. The short grass, buffalo and blue grama, had evolved as the perfect fit for the sandy loam of the arid zone. It could hold moisture a foot or more below ground level even during summer droughts, when hot winds robbed the surface of all water-bearing life. In turn, the grass nurtured pin-tailed grouse, prairie chickens, cranes, jackrabbits, snakes, and other creatures that got their water from foraging on the native turf. Through the driest years, the web of life held. When a farmer tore out the sod and then walked away, leaving the land naked, however, that barren patch posed a threat to neighbors. It could not revert to grass, because the roots were gone. It was empty, dead, and transient."

—Timothy Egan, The Worst Hard Time: The Untold Story of Those Who Survived the Great American Dust Bowl

Read this book.

Thinking Green

I love a good idea. I don't care where it comes from: me, you, other designers, the janitor. I'll gladly stand on the shoulders of people smarter than I am—which is a nice way of saying I'll steal their ideas. But I'll at least give them credit.

So in that spirit, here is longtime sustainability advocate Arlie Middlebrook's contribution to our lively, and necessary, conversation about global warming. I've highlighted the ideas that I find particularly insightful, but the insights (and words) are hers:

"THIRTEEN WAYS TO STOP GLOBAL WARMING
"Save Water and Have a Beautiful Natural Garden

"1. Plant a California native garden utilizing plants that naturally occur at your site. Native plants thrive where they have evolved and are accustomed to, it can survive on annual rainfall. The establishment period is 2 years.

"2. Protect your watershed. The less impervious surface you retain on your property, the more rainfall will stay on your property. When you create a garden, try to retain all of your rainfall on your property. If you have concrete on site, renew, reuse or recycle it in creative ways, such as breaking it up and re-laying it for a porous driveway or patio, stacking it for raised beds or planters, staining it and re-laying. It as attractive stepping stones or recycling it for future use by others. City recycling centers will accept your broken concrete: http://www.sjrecycles.org/business/cddd-certified-facilities.htm

"These facilities will let you pick up recycled concrete as well.

"3. Don’t use new concrete in garden construction. After the burning of fossil fuels, the manufacture of cement is the number two contributor to greenhouse gas emissions. If you must use concrete, limit its use and request that ‘fly ash’ be used as an additive, or use porous concrete. Fly ash is a byproduct of burning coal and in addition to being a filler actually improves the concrete. Ask your contractor to add it to the mix. http://www.flyash.com/flyashenvironment.asp

"Porous concrete is comprised of pea gravel and concrete. Water drains through it. Several local concrete companies now supply porous or ‘pervious’ concrete, e.g. http://centralconcrete.com/pervious_concrete.html

"4. If you must irrigate, do not use spray/sprinkler systems. A sizable amount of the water is lost to evaporation. Use drip, soaker, bubbler, microspray or an underground irrigation system. The one exception is using overhead spray to establish a native bunch grass/wildflower meadow during the establishment period.

"5. Lose your Lawn! Up to 60% of household water is used on lawns. And throw away your lawn mower. Two cycle engines are the most polluting engines in America. Replace your lawn with a native meadow, native ground cover or a turf substitute. FieldTurf makes a replicated grass product that looks just like grass and has a natural feel, yet is manufactured from recycled plastic and ground up recycled tennis shoes. It is guaranteed for 15 years. http://www.fieldturf.com/product/nikeGrind.cfm

"6. Don’t use oil-derived pesticides, insecticides, herbicides or fertilizers. Compost and keep worm bins. Break the chemical dependence cycle. If it has the word “kill” on the package, be very wary of buying it. Your soil is alive and these chemicals can kill your soil (yes, even the fertilizers). Iron-based slug killer and safer ‘organic’ pesticides on the market including pyrethrins, essential oils and soaps may work more slowly, but you will come out ahead in the end. Reminder: All pesticides should be handled with care. Read labels carefully.

"7. Register your garden as a certified national wildlife habitat. (National Wildlife Federation http://www.nwf.org/backyardwildlifehabitat/createhabitat.cfm). Encourage children to visit your garden. Create places for frogs, birds, butterflies, toads and lizards. Create a small water feature. Leave detritus for animal cover and protection. Be a part of educating the next generation to feel connected to Mother Earth and learning the responsibilities of protecting Her.

"8. Use solar power to operate fountains, gates, lighting and power in garden sheds and cottages.

"9. Grow some of your own food organically. Plant fruit trees and vegetables as landscaping plants. If you can’t harvest your food, contribute it to those who need it. Work with local non-profit harvesting agencies such as Village Harvest: http://www.villageharvest.org/

"10. Use recycled material and products and certified sustainable products in garden construction. Trex, for example, is made primarily with recycled plastic grocery bags, reclaimed pallet wrap and waste wood. Beware: not all composite woods use recycled products. Use ‘Forest Council Certified’ wood and other recycled materials existing on site. Check http://www.RecycleWorks.org for materials you need.

"11. Buy from local suppliers. Limit your driving. Order materials online. Have materials delivered to your site.

"12. Use tree trimmings for mulch or recycled products like Pro-Chip, which is produced from curbside recycled garden waste. Apply generously to a depth of three inches minimum. It keeps your soil moist, reducing the need for irrigation. Many local tree service companies will give you mulch for free. Pro-Chip is available at local landscape supply companies, like South Bay Materials, as well as from BFI http://www.interquix.com/organics/decmul.htm

"13. Use weed cloth under mulch. This will allow the native plants to become established by repressing invasive weeds that can sneak through mulch. Four hours of weeding in the sun will having you wishing you had used weed cloth. Install it from the start and smile every time you walk by your weed-free garden beds."

I know I've already touched on some of these issues in previous posts, but Arlie's words are a good reminder. Do the right thing. Do it in small doses. And before you know it, you will be the change we need to see in this world.

The High Cost of Nitrogen

Inspired by Al Gore, House & Garden's garden guy Tom Christopher has written an eye-opener about "the cost in fossil fuels of the synthetic nitrogen fertilizers we apply so lavishly to our yards and gardens":


"After a bit of research and doing the math, I have found that [Gore] is right. The raw material for all synthetic nitrogen fertilizers is anhydrous (water free) ammonia, which is manufactured by combining hydrogen from natural gas with atmospheric nitrogen. This is an extravagant process: to produce one ton of anhydrous ammonia requires the consumption of 33.5 million British Thermal Units (BTU's) of natural gas. According to a 2001 U.S. government estimate, that's almost exactly half the quantity of gas needed to heat the average home in one of our northeastern states for a whole year.

"A farmer may need the fertilizer (though synthetic nitrogens are a relatively inefficient source of this nutrient because so much of what is applied simply leaches away through the soil to pollute groundwater and streams); what I can longer justify as a home gardener is my consumption of this costly stuff. Currently, I'm putting in a lawn as a fire-break and tick-free zone around our house in the country. If I were to plant a half acre of Kentucky bluegrass and fertilize according to the recommendations on the fertilizer bags, I'd apply a total of as much as 85 lbs. of synthetic nitrogen annually – consuming in that way more than 1.4 million BTU's of natural gas."

Whoa.

Obviously, nitrogen is necessary for plant development; we just need to be a little more thoughtful about how we use it and where we source it. Nitrogen-fixing cover crops, "grasscycling" with a mulching mower, and dressing the soil with well-composted manure can all increase your nitrogen delivery organically, and in fact counter some of the damage done by the production, and application, of synthetic fertilizers.

Where Have All The Butterflies Gone?

Just when we were preparing to celebrate the burgeoning population of painted ladies and other butterflies,
"Wild fluctuations in California's winter and spring weather have hurt fragile butterfly populations, causing numbers to fall to the lowest in more than three decades and increasing the concerns of scientists about long-term declines linked to climate change and habitat loss."
The full, depressing story is in the Chronicle.

Jewels on the Wing

[Note: Verdance clients originally received this article in May, as part of our free monthly newsletter on gardens and gardening. To subscribe to the newsletter yourself, please register at our site.]

Recently I read that the number of monarch butterflies migrating from North America down to Mexico has fallen an astonishing 75% -- even after 75% of their population already was lost to a freeze on their overwintering habitat in 2002. At this rate, monarch extinction seems likely in years, not decades or centuries, raising the gloomy prospect of a future when our children or grandchildren never get to delight in these winged jewels.

Studies of why butterfly populations are declining indicate a complex web of causes including deforestation, climate change, and pesticides. Whatever the reasons, though, we each can still do small things to slow the decline.

The best way to attract adult butterflies is to plant a garden that includes the vital milkweed plus sunflowers, zinnias, marigolds, phlox, petunias, butterfly bush, black-eyed susans, lilies, cosmos and daisies. Even without such an intensive habitat in our yard, most of us can integrate a few of these plants -- and collectively create a butterfly garden that spans acres.

It's also important to encourage butterfly caterpillars. The Sunset Western Garden Book lists plants whose foliage is good caterpillar food; there is a broad palette to choose from (broccoli -- who knew?), and it's easy to tuck a few into any garden. If you would like suggestions on butterfly plants whose foliage or flowers will complement your existing landscape, it would be my pleasure to help.

Perhaps the most important step you can take is to avoid using pesticides -- even "natural" ones such as Bacillus thurigenesis (B.t.) -- that kill indiscriminately. Always try the most benign and pest-specific solutions first: for instance, a sharp jet of water knocks aphids off of leaves and flower buds, and non-toxic oils of neem, garlic, mint or clove discourage ants, mosquitoes, leafhoppers and thrips.

And above all, appreciate the graceful acrobatics and fragile beauty of every monarch, anise swallowtail, and mourning cloak you see. Currently a spectacular migration of painted ladies is making its way through the Bay Area; taking the time to notice them will create a warm place in your heart that will endure long after the last butterfly has fluttered by.

[Update: there are quite a few swallowtails floating around, and on 6/10 my client in Berkeley reported, "Amazingly we have hundreds of Monarchs hanging out in our neighborhood this year. First time we have seen it since we have lived here. Has lasted three days so far. Kind of cool."]