My wife, Suzanne, and I built our cottage in the Berkshire Hills of southwestern Massachusetts six years ago. And I mean that literally—together with our late son, Matthew, we contributed our labor to nearly every stage of the process. We helped to clear the site and to raise the frame of hewn pine timbers, and supplied unskilled labor to the carpenters. Incidentally, if you enjoy thrillers, I recommend you try standing by while your 13-year-old son attacks a wall with a Sawzall® to cut openings for windows. My wife and I did all the painting inside and out; I taught myself how to mix and apply stucco so that Matt and I could dress the exterior of the foundation.

Given this history of self-help, I certainly wasn’t going to hire landscapers to install a garden. That’s one reason the landscaping has lagged—finishing the outdoor environment doesn’t have the same urgency as making sure the house itself is weather-tight and habitable. Gradually, though, we’ve created a lush vegetable garden and what I hope will one day be a lush little orchard of cider apples.

This summer, Suzanne shooed me out of what has become her kitchen garden. As a result, I have had time to address the decorative areas of the landscape. I chose to attack two problems simultaneously. I’d clear away some of the heaps of stone excavated out of what became our cellar and at the same time build walls to enclose a court in front of the cottage.

Stone is my favorite material for landscape construction. Though it’s time-consuming to install, stone is maintenance free once in place. It’s durable, typically increasing in beauty as it ages and acquires the patina of time. What’s more, if you use a locally collected stone, as I was intending to do, it perfectly integrates your construction into the landscape. A wall or terrace or flight of steps will look as if born of the land itself, rather than human hands.

Best of all, building with stone, though strenuous, can be a remarkably forgiving process. The key is to avoid the use of mortar and lay your stone “dry,” bedding paving stones in sand or grit and building walls by stacking stone on stone. This style of construction has two advantages for the amateur like me. If you make a mistake, you can disassemble whatever you have been building and reassemble it in a better fashion.

The second advantage of “dry-stack” construction is that it is less vulnerable to the weather than mortared masonry. If you miscalculate the foundation of a mortared stone wall, winter frost or a slow settling of the soil will shatter your work. Dry-stack walls, though, have the ability to adjust. Stones can ride up with the heaving of the frost to settle back into place with the spring thaw; a slight subsidence of the underlying soil may create a dip in your wall but it won’t destroy it. This is the secret of the classic New England stone wall’s longevity—they move with the times.

The basics of dry-stack wall building are easily learned. I enrolled in a couple of weekend-long workshops, one with Japanese-trained landscape designer Julie Moir Messervy, the other taught by master mason Neil Rippingale of the Kentucky-based Dry Stone Conservancy. (The photo is of a wall I helped to rebuild during Julie Messervy’s workshop.)

This brief period of instruction hardly made me a skilled craftsman. My walls don’t have the precision and polish of Neil Rippingale’s work, and I can’t begin to match his speed and efficiency. Thanks to what he and Julie taught me, however, I can assemble a durable, attractive dry-stack wall if I take my time.

This summer, I’ve already completed about 70 linear feet of a wall 30 inches wide at the base and 26 inches high. In the process, I’ve cleared away much of the debris left behind by the excavators of our cellar. Another 60 or so feet of wall and I will have framed my little court.

In my next post, I’ll address the issue of sustainable (and inexpensive) sources of stone for those without a natural supply, and some of the techniques involved in the dry-stack process. In the meantime, I urge you to check out Julie Messervy’s Web site and that of the Dry Stone Conservancy. Their different perspectives on this work, one (Julie’s) shaped by the Japanese tradition, the other derived from northern Europe, neatly complement each other.

A recent column in The New York Times caught my eye: Author Carol Kaesuk Yoon was lamenting the death of taxonomy. I don’t know what her credentials are, but I have heard some similar, if less dire, concerns expressed by personnel at NYBG’s William and Lynda Steere Herbarium. One reason for the rapid expansion of NYBG’s collection of preserved plant specimens in recent years has been the number of “orphaned” herbaria collections it has adopted. These are collections that were assembled by botanists at universities and other educational institutions and then abandoned when research priorities changed. Often, such collections are important for the perspective they provide on the flora of a particular region or on the history of a flora. If the NYBG botanists feel that the endangered collection is sufficiently important, the Garden has incorporated it into its own Herbarium. NYBG scholars have expressed to me their concerns about the way in which such de facto centralization has been narrowing the foundation that supports their disciplines.

And yet, I have seen over the course of my career in gardening a notable expansion in the use of scientific names for garden plants. This, I think, reflects in part the growing sophistication of American gardeners. As our landscapes have acquired more and more exotic treasures, the old system of common names became inadequate to keep them all sorted. Knowing a plant’s scientific name brings with it an understanding of where that species fits into the flora and what its relatives are, and that in turn provides clues to a plant’s care. Besides, the owners of rarities want you to know that their plants are not common. If you are cultivating a rare (and expensive) jack-in-the-pulpit from Nepal, such as Arisaema speciosum, you not unreasonably want everyone to know that it is not the same as the jack-in-the-pulpit (Arisaema triphyllum) they see popping up spontaneously in the neighboring woods.

In addition, though, I believe there is another motivation at work, one that arises from the depth of our consciousness. Human beings have always found a special power in names. Knowing the correct name for someone or something imparted a degree of power over them. In many ancient religions the true names of the gods were kept secret. The ancient Romans, for example, concealed the name of their capital city’s guardian deity so that enemies could not seduce his support with offerings and prayers. In Jewish scripture, the divinity is often identified only by a series of four letters, YHVH, the “unutterable name.” Traditional cultures ranging from North American Indian peoples to Australian aborigine tribes had a practice of keeping their true personal names secret because of their belief that it embodied some part of their soul or self.
Maybe that’s why, when I come across an unfamiliar wildflower in the woods or fields around my house, I have to know its true name. I have to know where it fits into the local community. This is an impulse that was formerly less common among home gardeners. My mother, a great gardener who remains in many ways my inspiration, never bothered with scientific names. It stunned me, having learned my gardening from her, to arrive as a student at The New York Botanical Garden. The immigrant gardeners who then made up the horticultural staff often spoke poor English. All, however, were fluent in botanical Latin.

If you were shopping for shoes, you’d surely try them on before you purchased a pair. Similarly, when shopping for garden tools, you shouldn’t hesitate to take a spade or rake off the rack and check how it feels in your hand before wielding it. Other shoppers may stare, but don’t let that deter you. You and your garden tools will have a long and close relationship, and that means you want to select only good partners.

Does the handle fit your hand? If not, it’s going to give you blisters.

Does the tool feel well balanced when you brandish it as you would when working? If not, you’ll have to use more muscle to control the tool, and you’ll finish your day in the garden with an ache. The same type of tools come in all sorts of different sizes—a stainless steel garden fork I inherited from my mother is a great tool, but not the one for me. The length of its handle was perfect for my 5-foot-4-inch mother, but I’m 5 feet 10 inches tall, and for me to use my mother’s fork requires an uncomfortable stoop.

If you are over the age of 50 (as I am) you’ve probably noticed that you are less muscular than you used to be—even if you have stayed active. That’s due to a condition known as sarcopenia that typically appears with the onset of middle age. Sarcopenia is a gradual decline in muscle mass caused by hormonal changes and a decline in your ability to synthesize protein and so grow new muscle tissue. Exercise and a healthy diet can slow this process but won’t stop it altogether. Which means that you (like me) are likely to find as you age that the tools that once suited you may become uncomfortably heavy.

For example, for 30 years my favorite digging implement was the full-strap nursery spade I bought from A.M. Leonard, Inc., the mail-order (and now web-based) tool company that has been a stand-by of horticulturists since 1928. This spade has a heavy, forged, alloy steel blade from which broad steel straps extend up the full length of the front and back of the 27-inch ash wood handle. This makes the spade virtually unbreakable; if you sharpen the bottom edge of its blade, it will, when propelled with sufficient force, slice through the thickest tree root or the hardest of hardpan subsoils. But this spade weighs a full 7 pounds, and I find it exhausting to wield for very long these days—and likely to provoke my tennis elbow. Recently, I’ve been finding much more compatible what used to be the second string, my English-made Spear & Jackson spade, a solid but less formidable tool that weighs in at 5 pounds, 3 ounces.

A.M. Leonard offers a number of lightweight tools, such as lopping shears with aluminum alloy handles, that are better suited to middle-aged or senior gardeners. It also sells long-handled spades that offer superior leverage to the traditional short-handled models and so are easier on the back.

Walt Nicke’s Garden Talk is another great source of lightweight and ergonomic tools.

Whether young or old, however, you should take your time when shopping for garden tools. Look around, check a few different sources to see what is available before you pull out the cash or credit card. The gardener who waits until the yard is covered with fallen leaves then rushes down to the nearest hardware store to grab whatever rake comes to hand is going to pay a high price in more ways than one. Let this sort of procrastination become a habit, and you’ll fill your tool shed with a mismatched menagerie of stopgaps. That’s a sure recipe for gardening misery and unsustainable labor.

In my last post I made a case for upgrading your garden tools. A tool, after all, is the means by which you convert your energy into tasks completed. A poorly designed, poorly made spade or rake or pruning shears is like a gas-guzzling automobile: You don’t get much in the way of results for the energy you invest. Fortunately, if you know what to look for when you shop for gardening tools, you’ll find that high quality doesn’t necessarily mean high price. There are lots of moderate-priced tools that offer perfectly adequate quality. Identifying such bargains isn’t difficult, either, if you learn to recognize a few basic clues to quality.

When I’m tool shopping, I start by examining a tool’s handle. If it’s made of wood, it should be of ash (preferably white ash) or hickory. Typically, you’ll find this information specified on the tool’s label. In addition, the wood should be knot-free and straight-grained. For the greatest strength, the handle should be set so that the long, elliptical “flowers” of the wood grain face to the sides when you use the tool and not to the front and back. Fiberglass and steel handles are stronger than wood, but generally heavier and less resilient; tools equipped with these handles tend to be more tiring to use. A plastic handle is generally the mark of an economical tool, but that’s not necessarily bad. Scrutinize the rest of the tool, and if it seems of good quality, enjoy the savings that an inexpensive but durable plastic handle can bring.

Besides inspecting the handle itself, check, too, how it attaches to the blade of the tool. In less expensive tools, these two parts are commonly joined with a tang and ferrule—a metal spike (a tang) at the blade’s top is driven up into the handle, which has been wrapped with a metal band (the ferrule) to keep it from splitting. A tang and ferrule joint can be quite strong, but if the wooden handle shrinks—and with time that’s likely—then the joint loosens. A far stronger and more durable joint is one in which the top of the blade has been forged into a socket and fitted around the handle’s base. A solid socket joint, as this is called, is usually a clue to a high-quality tool.

Another indicator of quality is the type of steel of which a tool’s metal parts are made. High-carbon steel is the traditional material for fine tools. Stainless steel tools are more expensive, but if you are the type of gardener who leaves spades and forks out in the garden, then the rust-proof stainless is a good investment.

Examine the welds where one piece of a tool joins another: On a good quality tool, these will be smooth and neat. Examine also any cutting edges—these should be sharp but also smooth, free of any imperfections or “burrs.” Moving parts, such as the cutting blade of a pruning shear or lopper, should move smoothly and easily, and there should be no “play,” no wobble, in the pivot around which the blade turns.

Keep these basic hints in mind and you’ll find it easy to separate the good quality tools from the labor-wasting junk. In my next post, I’ll discuss how you determine if a tool is of a size that fits you.

How to Read a Tool:
You can tell a lot about a tool just from a quick read of the label—manufacturers often reveal as much by what they don’t say here as what they do.

high carbon steel: an alloy of iron and carbon. Tough and hard, takes a sharp edge, the best all-round tool steel.

stainless steel: carbon steel alloyed with chromium and nickel. Expensive but extremely rust-resistant, makes a maintenance-free tool.

tempered: indicates that, after the steel was shaped into the tool it was reheated to change its chemistry and make it tougher and less brittle. Besides being less prone to breakage, a well-tempered tool is easier to sharpen and stays sharp longer.

gauge (as in “16 gauge”): A measure of the thickness of the metal used in forming tools such as shovels. The higher the gauge number, the thinner the steel. A shovel destined for extra-hard use should be 14 or 15 gauge; 16 gauge steel is fine for average usage. Avoid any lighter shovel, such as an 18-gauge one.

heat-treated: see tempered

forged, drop-forged: A tool whose blade or metal head has been formed by mechanically hammering or pressing a piece of heated bar steel. Forging allows precise shaping, producing a stronger, better-balanced tool

stamped: A tool whose metal parts were formed by cutting and bending a piece of sheet steel. This produces a lighter, cheaper tool, but also one that is typically weaker and less durable than a forged one.

solid hardwood handle: A red flag! A host of inferior, brittle woods qualify as “hardwood.” A wooden handle should ideally be made of ash or hickory, and if this is the case, the label will surely say so.

Efficiency is the heart of sustainable gardening—you want to use resources sparingly and get the best return for whatever you invest. Including yourself.

That’s something most gardeners seem to forget when they shop for tools. Tools are the means by which you translate your ideas and energy into reality. A really good tool, one that also fits you, maximizes your effectiveness. A poorly crafted tool or one that is inappropriate for you or the task makes the job much harder than it has to be and guarantees poor results.

Actually, to describe the way in which most gardeners acquire tools as shopping is an exaggeration. Most go to the garden center or a big-box store and take whatever happens to be sitting on the shelf.

Would you buy a suit or a pair of shoes without trying them on? Yet when was the last time you tried on a tool before you bought it?

And if you decided to bake a cake, you wouldn’t use a cast iron skillet just because that was the first pan that came to hand. But that, time and again, is what I see other gardeners doing when they work their plots. They prune a tree with an old carpenter’s saw or turn the soil in a bed with a contractor’s shovel.

My wife, who is an excellent gardener, claims that I’m a tool snob. She’s right. I tend to take my enthusiasms to an extreme, and as my wife’s green-thumbed achievements prove you don’t have to use expensive, hand-forged tools to achieve great results. In fact, I’ve found tag sales to be an excellent source of inexpensive but serviceable tools, since the quality of old hand tools is often better than that of contemporary products.

In my own defense, though, I will say that I’ve noticed that when my wife is pruning she always uses the Okatsune 7-inch bypass shears I bought for her. The Okatsune shears are smaller than the No. 2 Felco ones I use, so they fit her hand better. Likewise, when she’s digging, she uses a beautiful T-handled Dutch spade I bought years ago but rarely use because the handle is too short for me—I have to stoop to use that tool, which is hard on my back. My wife is a couple of inches shorter than I am, and the Dutch spade fits her perfectly.

Selecting garden tools is a lot like choosing friends (except more important). In both cases it’s a very personal process, and making the right choice depends on who you are. That’s why I’m not going to recommend specific tools besides the pruning shears I just mentioned. Instead, in my next post I’ll share a list of clues to quality you can look for when shopping for gardening hand tools.

In my last post I described the EPA’s program to promote rain gardens as a way to cleanse storm runoff and the challenge I think de-icing chemicals may pose to this scheme. Briefly, by installing shallow, thickly planted and unlined basins along streets and parking areas, researchers have found that it is possible to trap storm water, which would otherwise serve as a source of pollution to nearby waterways. The storm water soaks into the soil around and under the basins, and pollutants are extracted by plant roots. This benefits the environment while greening urban areas, and wastewater is treated without any expenditure of energy. An ideal, sustainable solution.

Except that, in cold winter regions, rain gardens will concentrate roadway de-icing chemicals that are toxic to plants. So far, no one (as far as I can tell) has researched how to cope with the effects of that. Certainly, no one at the two-day workshop I recently attended, Managing Wet Weather with Green Infrastructure, had any answers when I raised this issue.

As I sat sipping a cup of federally funded coffee (the EPA had sponsored the workshop) during an ensuing break in the programs, I recalled one of the very first landscaping projects I undertook after graduating from NYBG’s School of Professional Horticulture: a job restoring the landscaping of an historic estate that Columbia University had turned into a geological observatory.

The landscaping had been designed in 1929 by Olmsted Brothers, the firm founded by the creator of New York’s Central Park and the Boston park system, and the campus still retained the skeleton of Olmsted’s pastoral vision. Right at the entrance, though, the Columbia scientists had imposed a large and ugly parking lot, framed with a narrow strip of desiccated turf. This blighted every view, and I was determined to hide it. I did this by enclosing it with an irregular screen of fast-growing and evergreen white pines. These trees were native to the area and I hoped that they would mature into what would appear a natural grove. As soon as I got their rootballs into the ground, though, I realized I’d made a mistake. White pines are sensitive to salt, and the observatory’s grounds crew spread that by the ton every winter to erase every scrap of ice from the surrounding road and adjacent parking lot.

After considerable nail chewing, I figured out a way to rescue the situation. I shielded the pines by lining the road and lot with thick bands of salt-tolerant shrubs—bayberries and rugosa roses that I remembered from trips to the beach and inkberry hollies (Ilex glabra) that also grow naturally on coastal dunes. By trapping the salty spray from the snow plows, the shrubbery belts allowed the pines to thrive.

I predict that, as rain gardens become the preferred method of dealing with storm water in our northern landscape, there is going to be an explosion of interest in such seaside plants. Ornamental grasses will also play an important role: One of the effects of infiltrating the soil with salt is to create a sort of artificial drought. The salt mixes with water in the soil and disables the pumping action of plant roots. Many grasses (see the list below) not only tolerate salt, they also cope well with drought.

Here are some salt-tolerant ornamental grasses, as listed on the Bluestem Nursery Web site.

Calamagrostis: all species
Chasmanthium latifolium
Elymus magellanicus
Festucas: all species
Helictotrichon sempervirens
Panicum amarum ‘Dewey Blue’
Panicum virgatum: all species
Pennisetum alopecuroides

For a more extensive list of salt-tolerant garden plants, see the North Carolina Cooperative Extension recommended list.

Managing Wet Weather with Green Infrastructure was the title of the two-day workshop sponsored by the U.S. Environmental Protection Agency (EPA) in Hartford, Connecticut, last month. I couldn’t resist—it has been the rainiest summer I can remember, and personally I hadn’t discovered any management techniques except martinis.

It turned out to be a very sobering, though not at all dry, two days. Storm runoff is one of the principal sources of pollution in our rivers, streams, lakes, and estuaries. In many communities, the storm drains feed it into the sewer system so that any substantial storm has the effect of overwhelming water treatment plants and flushing raw sewage into waterways. Even where separate pipes have been installed to carry off storm water without mixing it with sewage, the runoff picks up a load of animal feces, fertilizers, pesticides, and heavy metals on its way to the storm drain, making it a cause for stream and habitat degradation, even beach closings.

Instead of letting storm water turn into a liability, the EPA experts suggested, treat it as a resource. Trap it before it enters the drainage system, they advised, and use it to irrigate specially designed “rain gardens” and planters so that the storm water soaks into the soil and naturally cleanses itself. I watched as a series of PowerPoint presentations illustrated just how attractive the results could be.

Most notable was the work of landscape architect Kevin Perry, who has turned the city of Portland, Oregon, into an international leader in this sort of redesign, turning what had been bleak expanses of pavement into lush urban oases.

Given the pressure from the EPA to address storm water pollution, it seems like more a matter of when than if our communities are going to follow Portland’s example. This will present gardeners with endless opportunities for exercising their creativity. It’s also going to demand ingenuity. For example, Kevin Perry had lots of sound advice on constructing shallow basins to collect storm water and plants that flourish in rain gardens in Portland’s mild climate. He was stumped, however, when I suggested that winter de-icing chemicals will make a different plant palette necessary in the Northeast. In fact, nobody at the workshop, not even the delegates from the EPA, could offer any insight or experience about this issue.

In my next post, I’ll propose what I think may be a solution to this problem. See what you think. In the meantime, for more information about rain gardens and green infrastructure, see the EPA Web site.

For more information about plants and salt injury, see the University of Wisconsin Cooperative Extension publication on the topic.

Two southwestern states, New Mexico and Texas, have already adopted gray water regulations similar to those of Arizona. Nevada has resisted: Authorities there fear that diversion of gray water from the sewer system will reduce the amount of treated wastewater available for return to the Colorado River. This is important because the amount of freshwater the state can withdraw from the river is connected to the amount of water it returns. Montana, where water shortages and drought are becoming chronic, passed a law allowing the installation of gray water irrigation systems at single family homes in 2007 and extended that right to multi-family dwellings and commercial buildings this year. Oregon and Washington are considering loosening restrictions on the use of gray water.

New York, Massachusetts, and Connecticut have also examined the use of gray water as a means of stretching the public water supply and reducing the load on water treatment systems. Use of gray water irrigation systems is complicated in the Northeast, however, by climate. The type of inexpensive, above-ground plumbing favored in Arizona would be vulnerable to frost during northeastern winters; only relatively expensive subsurface distribution systems for gray water would continue to function during months when the soil surface is frozen. A greater obstacle to the use of gray water irrigation in the northeastern United States is the moister climate prevalent through the region. Because gray water does contain bacteria and pathogens, even if only in reduced numbers, it isn’t safe to store gray water without treatment for more than 24 hours. That means a gray water irrigator in, say, New York would often be forced to water when the garden didn’t need the extra moisture. Plants are harmed as easily by too much moisture as too little

And, as was pointed out to me by the gray water expert at the Arizona Department of Environmental Quality, the potential for health hazards developing in the Northeast is far greater. Because the habitat is much less arid in the Northeast, any water released into it will persist far longer than it does in the Southwest. The risk of gray water pooling on the soil surface or running off across the surface of the ground becomes far greater in a humid climate.
For this reason, interest in gray water in the Northeast has tended to focus on the use of this water source for flushing toilets. See BuildingGreen.

One exception to this rule is found across the street from The New York Botanical Garden at the Bronx Zoo, where a new, multimillion dollar pair of restrooms was installed in 2007. The relatively small quantity of water visitors use to wash their hands drains from the sinks into a gray water garden right outside.

Gray water advocates argue that during the 20 years since they began installing their irrigation systems during the drought of the late 1980s, no instance of disease transmission via gray water has ever been recorded. In fact, a year-long study conducted by the City of Los Angeles Water Reclamation Office in which gray water systems were installed in eight residential landscapes no human disease pathogens were found in the soils irrigated in this manner. It’s worth noting, though, that all these systems were of tested types and were professionally installed. (For a more cautious assessment of the hazards of gray water use, see the Barnstable County, Mass., Department of Health and Environment Web site and the Drought in Georgia pages.)

As the popularity of gray water recycling grew, the state of California decided it had to take some role in regulating gray water use because of potential health hazards. Ultimately, the state chose to err on the side of caution. It treated the installation of gray water irrigation systems much like any other home construction project. It decreed that a detailed plan for any proposed gray water irrigation system (complete with soil tests) must be filed to secure a building permit and that an inspection would follow completion of the project. The state also insisted that distribution of the water must be made through a specified type of leach field or drip irrigation system buried at least nine inches below the surface. The result has been to make gray water systems enormously expensive to install—the estimated average cost runs to $5,000 or even more.

This hasn’t discouraged California gardeners. Only a handful of gray water permits have been issued since the passage of the ordinance more than 17 years ago, but advocates say that more than a million state residents have installed systems illegally. The most popular type of system has been the so-called “laundry to landscape” type, in which a hose or pipe is attached to the drain of the family clothes washing machine. The simplicity and low cost of installation makes this system attractive: the washer’s pump provides all the power needed to force the gray water out and into the garden. There’s an inadvertent advantage as well in that wastewater from washing clothes typically contains far fewer bacteria and potential pathogens than human bathwater.

Gray water advocates are pushing the California state government to recognize the reality of gray water use by moving to a more hands-off stance, similar to that which the state of Arizona has adopted. In 2001 Arizona passed a blanket permit for the whole state. It published a list of 13 guidelines for safe gray water use, stating that if homeowners follow these standards and limited their gray water use to less than 400 gallons a day per residence, their system would be, automatically, legal. The state only becomes involved with defective systems after the fact, when neighbors call in complaints about flooding or other violations. When I discussed this with a spokesman for the Arizona state Department of Environmental Quality, he said that such complaints are quite rare. He pointed out that in a desert habitat, which describes most of Arizona, a modest quantity water released into or even onto the soil rapidly evaporates. Persistent water logging or flooding and the spread of water-borne pathogens are unlikely in these circumstances.

The California Department of Housing and Community Development is scheduled to submit a new Greywater Standard based on the Arizona model for approval by the state’s Building Standards Commission at a meeting on July 30. If accepted, the new regulations would allow the installation of gray water systems fed by a washing machine and one other approved fixture such as a shower without a permit, as long as the installer, as in Arizona, follows a short list of guidelines.

Water Conservation Alliance of Southern Arizona has estimated that gray water reuse can save 50,000 gallons of water per residence per year in that state. Similar savings could have a huge cumulative effect in its neighbor to the north, California, whose population is more than five times greater.

During the last round of droughts in California, back in the late 1980s through the early 1990s, the gardeners of that state were often forbidden to use potable water to irrigate garden plants. This created a lively market for used water, water that could be legally applied to the landscape. I remember visiting Santa Barbara then and seeing entrepreneurs peddling treated wastewater door to door. They’d drive a tanker truck down to the sewage treatment plant, fill it up from the outflow, and then, for a hefty fee, spray the recycled water onto your garden. Bootlegged water was also for sale, if you had a connection. People would return from vacations to find that someone, in the dark of night, had filled a truck from their hose. The bootleggers would sell this stolen water to gardeners who knew better than to ask too many questions; the returning vacationers would only become aware of the theft when they later received a truly astonishing water bill.

The more self-reliant gardeners eliminated the middleman, collecting and recycling wastewater before it entered the sewage and storm drain system. They made use of a class of water known to plumbers as “gray water.” Gray water (also sometimes spelled “greywater” or “graywater”) is water that has been used for some household purpose such as a bath or shower, or washing clothes or dishes; as such, it is no longer potable but is still clean enough for use in irrigating plants. Typically, it constitutes 50 to 80 percent of the water that homeowners discard into the septic or sewer system. The remaining wastewater (20 to 50 percent), which is classed as “black water,” comes from sources such as toilets, which may be contaminated with human waste. This cannot be safely recycled without intensive treatment.

The benefit of gray water recycling is twofold. It allows a gardener to irrigate without drawing additional water from a well or water main and so reduces the demand on the aquifer or public supply system. At the same time, by diverting wastewater from the drain, it reduces the stress on a septic system or public water treatment plant. Indeed, in yet another illustration of the “one man’s poison is another man’s meat” principle, a number of the contaminants in gray water such as nitrates, potassium, and phosphates that must be treated as pollutants at the water treatment plant act as fertilizers when the gray water is applied to the garden. Other contaminants, such as sodium and chlorides, are less plant-friendly, but the presence of these can be minimized by the use of soaps and detergents designed to be more environmentally friendly such as the Oasis line of products.

As beautiful as gray water use is in theory, public health departments have worried that reality could be very different. Their concern is that poorly designed and installed gray water irrigation systems will flood residential neighborhoods with wastewater. In a worst-case scenario, gray water from a home with a sick resident could, theoretically, spread dangerous pathogens across the landscape.

For more information about using gray water in the garden, see the Web sites of:
UMass Extension,
Oasis Design,
and the University of Arizona’s Water Resources Research Center.