My Pile: Inner Workings (Part I)

I’ve set up my pile for winter as best I can. It’s got all the makings it needs – layer upon layer of dead plant stuff mixed with an array of juicier, biodegradable organic material — to fuel the composting process that will take place deep inside my pile through the short days and long cold nights ahead.

Today, the last Saturday before Christmas, is when autumn turns to winter. For much of recorded history, the winter solstice — the day with the shortest period of daylight and longest night of the year — was marked by celebration, a time for feasting on the fatted calves of summer and the fermented grape and grain of the harvest fall. A final blowout before the start of famine season.

As the day marks the reversal of the ebbing sun, it also signifies a new beginning, the reawakening of nature, rebirth. Pagans celebrated the Yule holiday, and sacrifices were given to the gods to earn blessing on the forthcoming germinating crops.

Our modern “midwinter” holiday, with its Christmas trees and yulelogs, is a direct descendant of those customs, and I’m OK with that. But it can hardly improve on the idea behind the oldest known construct honoring the winter solstice: Newgrange, a neolithic structure in Ireland built around 3,200 BC. A large mound, built of alternating layers of earth and stones, with grass growing on top, the monument’s entrance is aligned with the rising sun on the winter solstice, when sunlight shines through a ‘roofbox‘ and floods the inner chamber. It’s called Ireland’s greatest national monument, and it’s all to celebrate this day. If my pile had the weight and significance of Stonehenge, it would be Newgrange — in 5,000 years.

I make the best use of this short day with a quick trip over to the beach with the dog and bring home a big bucket stuffed with the straw of salt marsh grass. I’ve gathered a pail full of kitchen scraps from the neighbors’ next door and set it beside my own smaller plastic canister of spent coffee grounds, chopped-up vegetables, broken egg shells and dinner-plate scrapings. Votive offerings were found in the inner chambers of Newgrange, and I will add these new offerings to my pile in kind.

Another neighbor, the older couple who lives on the western side of my property, had asked a few days ago if I could take the decorative pumpkins from their front stoop. They’ve long since served their symbolic purpose of the harvest season and Halloween, and it would be a waste to consign them to the trash when they could contribute their rotting plumpness to my pile. My son and I already have a supply of freshly roasted pumpkin seeds culled from our own porch set and tossed the rotting husks into the heap. Today I finish up the the season of giving thanks by smashing up the neighbors’ pumpkins and chunking them into my pile as well.

Pumpkins are a most welcome addition to my pile. A member of the Cucurbitaceae family, which also includes squash, cantaloupes, cucumbers, watermelons, and gourds, the pumpkin has been cultivated for a thousand years or more, first by Native Americans in the Southwestern United States, but today is grown mostly in the Northeast, and mostly near big cities to cater to the Halloween market.

The practice of decorating and lighting hollowed-out pumpkins and setting them on doorsteps to ward off evil spirits stems from an Irish folktale about a man named Stingy Jack, a tradition brought to these shores by immigrants uprooted by the potato famine. Long Irish story short: Jack was a drunk who successfully battled his demons but couldn’t quite make it to heaven. The Devil tossed him a lit ember straight from Hell — a bone, given Jack’s past shenanigans — and Jack placed it in a hollowed-out turnip to help light the way on his endless wanderings.

In all, 1 billion pounds of pumpkins are harvested in the U.S. each year, says the PennState Extension. Though I’m heartened by the fact that the season’s other decorative ornament — the Christmas tree — is often recycled, the fate of millions and millions of these pumpkins is, like that of old Stingy Jack, less certain, which is why I like adding their orangeness to my pile late each fall. Pumpkins are high in fiber, vitamin A, and like most vegetables, more than 90 percent water. Despite their heft, or perhaps because of it, their remains disappear without a trace in my pile but add measurably to it.

Using the hay pitchfork, I hollow out the top of the pile, exposing a steamy layer of moldy leaves. The buckets of kitchen scraps disappear into the mix, and I use a spade to shovel in about half of the pumpkin shards. I cover the lot with pitchforks of salt marsh grass hay, teasing apart the stalks with the tines so that the stems cover the top of my pile. Onto this springy bed of straw go the rest of the pumpkins. The bright orange rinds and mushy strands of flat pale seeds disappear as I twist the pitchfork deep into the mix.

With the start of winter just days away, it's time to say goodbye to the signature symbol of both Halloween and Thanksgiving -- pumpkins.

With the start of winter just days away, it’s time to say goodbye to the signature symbol of both Halloween and Thanksgiving — pumpkins.

I cover the pumpkins with two bedsheets of damp maple leaves dragged over from my neighbors’ backyard. Once again, the cover-up is complete, and my pile is largely on its own, left to its own devices.

As Ken Thompson writes in “Compost” (DK, 2007), “A compost pile is a complete ecosystem, a world in miniature.”

The inner workings of my pile are largely a mystery to me. Even soil scientists are still profoundly uncertain about what exactly takes place, biologically, underneath our feet. Michael Pollan and other close watchers liken soil to a frontier more unknown that the deep oceans or outer space. The humus that my pile produces is in many respects terra incognita.

I consider composting more a craft project than lab experiment. I am happy to let my pile do its own thing, with a certain amount of input and creative direction. That said, both the art and the science of making compost is well-developed and readily available, whether it’s from a book shelf at the library or simple online search term.

The University of Illinois Extension website, Composting for the Homeowner, provides a compendium of useful tips and academic research that seems clear, credible and worth sharing. There are many other such academic “extensions” of knowledge online and elsewhere about compost, including a few store-bought books that stock my own shelves, ranging from the earnest how-to guide to more free-form ruminations from ‘70s commune types turned cottage-industry composters.

While my pile gently heats, I explore the research and literature about compost. The more I learn, the more I realize I’m less a deus ex machina than silly old wizard behind the curtain. The more I think I do for my pile, the more I realize it will do its own thing anyway.

To whit, the UI Extension tells me: Backyard composting speeds up the natural process of decomposition, providing optimum conditions so that organic matter can break down more quickly. As you dig, turn, layer and water your compost pile, you may feel as if you are doing the composting , but the bulk of the work is actually done by numerous types of decomposer organisms.”

I’ll let the Extension explain further:

“Microorganisms such as bacteria, fungi, and actinomycetes account for most of the decomposition that takes place in a pile. They are considered chemical decomposers, because they change the chemistry of organic wastes. The larger decomposers, or macroorganisms, in a compost pile include mites, centipedes, sow bugs, snails, millipedes, springtails, spiders, slugs, beetles, ants, flies, nematodes, flatworms, rotifers, and earthworms. They are considered to be physical decomposers because they grind, bite, suck, tear, and chew materials into smaller pieces.”

Here I thought I was the master of the domain that is my pile. Not true. I am only the minder.

Master composter Ken Singh, profiled in a Rodale’s Organic Life article, puts it well: “The microbes in our compost are the best employees I’ve ever had. They work tirelessly. They don’t complain. They never go on strike. By golly, I love ‘em! All the networks of fungi and microbes in soil are interconnected. We’re part of that, too. One day we’ll end up back in the soil ourselves.”

Charles Darwin knew that earthworms were the real movers & shakers.

Charles Darwin knew that earthworms were the real movers & shakers.

More from the Extension:

“Of all these organisms, aerobic bacteria are the most important decomposers. They are very abundant; there may be millions in a gram of soil or decaying organic matter. You would need 25,000 of them laid end to end on a ruler to make an inch. They are the most nutritionally diverse of all organisms and can eat nearly anything. Bacteria utilize carbon as a source of energy (to keep on eating) and nitrogen to build protein in their bodies (so they can grow and reproduce). They obtain energy by oxidizing organic material, especially the carbon fraction. This oxidation process heats up the compost pile from ambient air temperature. If proper conditions are present, the pile will heat up fairly rapidly (within days) due to bacteria consuming readily decomposable materials.”

My pile on a frosty morning in December. What's going on in there?!

My pile on a frosty morning in December. What’s going on in there?!

“While bacteria can eat a wide variety of organic compounds, they have difficulty escaping unfavorable environments due to their size and lack of complexity. Changes in oxygen, moisture, temperature, and acidity can make bacteria die or become inactive. Aerobic bacteria need oxygen levels greater than five percent. They are the preferred organisms, because they provide the most rapid and effective composting. They also excrete plant nutrients such as nitrogen, phosphorus, and magnesium. When oxygen levels fall below five percent, the aerobes die and decomposition slows by as much as 90 percent. Anaerobic microorganisms take over and, in the process, produce a lot of useless organic acids and amines (ammonia-like substances) which are smelly, contain unavailable nitrogen and, in some cases, are toxic to plants. In addition, anaerobes produce hydrogen sulfide (aroma-like rotten eggs), cadaverine, and putrescine (other sources of offensive odors).”

There is much more that the Extension has to say on this subject, but at this point in the season my place in the ecosystem that is my pile is clear: My pile needs me to help keep it on a slow burn as long as I can with a judicious, even artful blending of energy, air and water.

Otherwise, my pile is just a big mess of leaves cluttering up my backyard. And what good is that?

My Pile: Breathing Room

It’s a balmy Sunday in mid-December,  and although the neighbors are busy decking out their homes and yards with holiday lights and decorations, it’s unseasonably warm. With a record high of  near 70 degrees today, I leave my own lights in their boxes in the attic and plan to devote the day to sprucing up the backyard and taking care of outdoor chores.

There’s wood to chop for the fireplace. I roll a few whole logs from the stack of sawed-up maple drying next to my pile. I stand them on end to split into chunks and soon have set aside enough cordwood to burn well into the new year.

Some of the maple logs are too long for the fireplace, or too knotty to bother chopping. But they will make good new replacements for the rotting logs that contain my pile. The two parallel walls of thick old stacked logs also serve as stepping stones for me to clamber up, and several are now too crumbly to safely perch on.

Today I plan to give my pile a good poking, using an 8-ft. length of rebar I snagged a couple years ago from a neighbor’s scrap bin. Standing atop the log walls requires a bit of a balancing act to thrust the bendy section of rusty, ribbed steel down into the heap of leaves.

I roll two new logs into place, improving both the sturdiness of the log steps and giving me new perches to sit on at the feet of my pile. I also like the look, as along the way I’ve also added some rakings of fresh leaves to the top of my pile. There is always tidying up to do in a backyard garden, especially one as active as mine.

Some of the busyness involved in chopping wood and shoring up my pile. Plus, old pumpkins from the neighbors...

Some of the busyness involved in chopping wood and shoring up my pile. Plus, old pumpkins from the neighbors…

My pile is like a sandbox for grown-up play. It offers endless opportunities to make things up in a playful yet industrious way. It reminds me of the forts we baby-boom suburban kids once made in nearby woods or construction sites to fight imaginary cold-war battles.

Which brings me to the rebar I use to poke my pile.

The rusty stick of half-inch steel weighs just a couple pounds, but climbing atop the log walls and thrusting it a couple dozen times into the midst of my pile gives me a good, quick workout. As an aerating tool, it does a fine job of making my pile more porous, for both water and air.

My pile needs to breathe. It may be chockful of dead stuff but it is a living thing, and to sustain the life within it my pile needs air.

“What you are doing when you construct an aerobic (with air) compost heap is creating the right environment for the billions of microorganisms that make the compost happen. Their food is the materials that you put on the heap,” counsels Nicky Scott in “How to Make and Use Compost.”

“A happy heap will have a balance of air and waiter, just like a squeezed-out sponge; the whole surface area is coated in water but there are air spaces in between. If the pile is too dense, squeezing out all the air, then all the beneficial life forms in the compost heap are not going to survive and will be replaced by the ‘bad’ microbes — the anaerobic (without air) ones that are responsible for all the bad odours you get from putrefying substances. This is bad news for your compost and if you put this material on your plants it can be toxic to them. So creating air spaces in the compost is vital.”

Turning, or tumbling, a compost pile is the surefire way to add big gulps of air to the process, but my pile is too big and unwieldy at this point in its life cycle. Using a hand aerator is much like performing CPR — a remedy used after the fact as a short-term fix.

I try to give my pile good lungs from the start, mostly by building it in layers and using plenty of porous material along the way, mostly the hollow reeds of salt marsh grass gathered from the seashore but also armfuls of spent tomato vines and flower stalks from the cutting garden.

Some years the deer allow me to grow sunflowers along the fence bordering the vegetable garden, and come the fall their thick fibrous stalks make excellent ventilation shafts for my pile. The soft centers rot out — think of sugar cane — creating hollow tubes for both air and water to flow.


Sunflower stalks, or reedy stems from perennials make good interior highways for air, water and things that creep and crawl.

Sunflower stalks, or reedy stems from perennials make good interior highways for air, water and things that creep and crawl.

Some compost experts advise starting a heap by first sticking a length of perforated PVC pipe in the middle, or a rolled-up tube of wire mesh fence, to serve as a more permanent chimney. I may try that trick someday but for this season will stick with my sticks of sunflower augmented by slender steel.

Jousting with my pile is also instructive.

With a few hard thrusts, back and forth, the rod drives deep into the pile. The rebar ribs make it thrum and give me sensory feedback through the vibrations in my gloved hands.  The rod zings like a tuning fork through a section of dried leaves. It tings like sonar when the blunt end strikes an oyster shell caught up in a collection of seaweed from the beach. What’s that tough but squishy part? The Jack o Lantern tossed in after Halloween?

An old length of rebar makes a good aerator for my pile.

An old length of rebar makes a good aerator for my pile.

I press harder, leaning into the bar of rebar when it meets the resistance of a thick patch of tightly packed mulched leaves. I press on, and when the tip meets hard ground I feel the jarring end note all the way up to my elbows.

Sometimes when I tug the rod back up and out of its tight pathway, jousting with my pile, it wins, and the pole slips through my gloves. I grab tight and pull harder, fearing that one of these days I’m going to stick the shiv of metal right up under my chin.

I jerk the rod free and clear, using its slender wobble like a tightrope walker to keep from teetering off the log wall.

I make a dozen or more thrusts from each side and front and back, varying the angle of entry each time, making a pin cushion of my pile. In my mind’s eye I see each punch hole as a slender tube of air for water to navigate, a superhighway for countless unseen bugs and bacteria to mix and mingle. I’m creating breathing room for my pile.

The piece of rebar also makes a handy thermometer to gauge the temperature of my pile. It's hot to the teuch!

The piece of rebar also makes a handy thermometer to gauge the temperature of my pile. It’s hot to the touch!

The butt end of the rebar glistens with steam. I pull my glove off to confirm: The rod is warm to the touch.

I wonder if the heat is caused by the friction of all my aerobics, so I stick the piece of cooling steel back down into the heart of my pile. I wait a few beats, then draw the end back out to take the temperature of my pile. The bar is hot to the touch. I take it as a good sign that inside my pile is a churning, burning mix of earth, water and air.

It’s smoking hot, my pile.

My Pile: A Soak and a Poke

My pile now sits, Buddha-like, in the backyard.

Over the past two months, I’ve made a dozen or so roundups of leaves, topping each new load on my pile with layers of grass clippings, seaweed, kitchen scraps, rabbit litter, coffee grounds and whatever other ready-to-rot organic filler I come across.

After all those additions, each followed by a fresh exhalation of air, my pile has assumed its winter repose. Its bulk seems permanent, immutable save for the tendrils of steamy vapor that waft up from its mounded summit on cold mornings.

I know underneath its mantle of damp brown leaves and flecks of seaweed, my pile is stewing. Left to its own devices, it will slowly cook, a crockpot of compost, through the winter.

But as they say, a watched pot never boils, and I can’t resist tinkering with my pile’s inner workings to stoke the process of turning its raw ingredients into a finished product of a new living soil called humus.

Over the winter, I’ll continue with my regular deposits of kitchen scraps and such. I carve out a hole in the pile with a pitchfork, upend a container of slop into the mix, then backfill the hole with a plug of leaves raked up from a corner of the yard.

These contributions are helpful, mostly for housekeeping, but only scratch the surface of my pile. And fully turning my pile with a pitchfork will have to wait until the spring, after my pile has had the still time of winter to cook down into a heap that’s more manageable in size.

What my pile needs now right now are big gulps of water and air. Without these essential elements and agents, the chemical process that is decomposition will slowly grind to a halt.

“The amount of water in your compost pile is fairly critical, but you have plenty of leeway in which to work,” writes Stu Campbell in “Let It Rot! — the Gardener’s Guide to Composting” (Storey, 1998). “If the moisture content is much greater than 60 percent, you run the risk of having an anaerobic pile; if it is much less than 40 percent, organic matter will not decompose rapidly enough because the bacteria are deprived of the moisture they need to carry on their metabolism. Of course, you can’t monitor the percentages, so in general try to make sure the materials in your pile have the moisture content of a well-wrung sponge.”

“This is COOKING, not BAKING, and you have a lot of wiggle room,” Mike McGrath fairly shouts in his “Book of Compost” (Sterling Publishing, 2006). “Not bone dry, not soaking wet; in the middle is just right. And if the Goldilocks method doesn’t work for you, purchase a moisture meter — you can get these inexpensive electrical probe devices online and at most garden centers. They’re great to have around if you have a lot of houseplants…”

The rains this fall have been plentiful, and regular. I try to time my yard cleanups in advance of a coming storm; even a modest shower tamps down the leaves atop the pile so they don’t skitter back across the yard when the front blows through. “Rainwater is the best kind to put on compost. It picks up lots of oxygen, minerals and microorganisms as it falls through the air, giving your compost an added boost,” Stu Campbell counsels.

But even the heaviest rain soaks down into my pile only a matter of inches, absorbed by the nearest layer of seaweed and chopped leaf mulch and repelled by the first strata of whole leaves with their waxy coatings.

Through the fall I’ve taken care to add as much moist material to the beginnings of my pile as possible; grass clippings, damp leaves and musty seaweed, and I’ve dampened the lot from time to time with a spritz from the hose. But I know from the vapors rising out of the top that the steam engine that is my pile is boiling off the water it has stored up inside.

My pile is thirsty.

This morning, a Sunday, is dry and warm for December – about 40 degrees. Just warm enough for me to turn on the garden hose and unfurl its stiff coils across the lawn over to my pile.

My pile burns through the water in its midst, even on a cold December day. Time to water it before the winter freeze sets in.

My pile burns through the water in its midst, even on a cold December day. Time to water it before the winter freeze sets in.

I stick the nozzle of the hose into my pile, jabbing it in as deep as it will intrude.  It’s always a deep mystery where the water goes and what unseen path it follows through the matrix that is my pile. Every minute or so I stub the end of the running hose into another spot underneath the leaves.

I calculate flow rates in my head. If my hose pours out a gallon every 30 seconds, that means eight pounds of liquid will weigh down the pile. But what path is the water taking? What will absorb it?

Usually by the time I can come up with some sort of answer, a trickle of water is wetting my feet at the pile’s edge. My pile needs water, but seems impervious to it. You can lead a hose to a compost heap, but you can’t make my pile take a drink.

I extract the hose and plunge the tip into another section, then another. It’s like dabbing a turkey with a baster, no matter how deep I stick the hose into the voids of my pile, the coursing water seems to find its way out back onto the ground surrounding it. My pile is not the sponge I think it is.

What my pile needs now is air.

My Pile: Chip, Chip, Hooray

With the yard cleanup complete and my pile put to bed for the fall, it’s time for another favorite backyard project: Dressing my beds of perennials and the forsythia hedges with a layer of fresh wood chips.

Over the years, I’ve spread truckload after truckload of the remains of all manner of local trees and bushes, sawed into chunks and run through an industrialized chipper by a local landscaping crew, flagged down to dump their results in my driveway. If it’s not grass or patio or pavement, the ground I tend is covered by a layer of what toney landscapers call arborist mulch, where it decomposes according to its own composition and timeline.

Each fall I replenish the garden beds of perennials with a fresh layer of wood chips.

Each fall I replenish the garden beds of perennials with a fresh layer of wood chips.

Wood chips aren’t quite as virtuous as compost, ecologically, but they do have their benefits to the backyard gardener. A four-inch layer of chips spread among my perennial beds prevents weeds from sprouting. It soaks up rainfall and slowly releases it, drastically reducing the need to water the flowers, bushes and shrubs that ring the perimeter of my property and surround the house.

A blanket of freshly minced trees gives the ground underneath the forsythia hedgerow and around the trees a uniform, manicured appearance, though for a few weeks my yard has the look of the kid with the bright new sneakers at school. And for a time, especially after it’s wetted by the first rain, a freshly spread layer of chips gives my yard a Christmasy, pine-scented smell or, when I happen upon a load made of black birch, a hint of Wrigley’s peppermint gum.

Some of my neighbors landscape their properties with store-bought mulch, made from coconut husks or nut shells or ground-up bark processed from who knows where – often dyed an unnatural shade of red or coffee brown. I prefer to get my wood chips unvarnished and for free, from nearby, and to spread them myself. I also like knowing where the chips come from, as an unsourced load of chopped-up tree or brush could introduce some blight or bug into my landscape. I’m pretty sure one year I got a nasty case of poison ivy after spreading a load of chips infused with ground-up ivy vines.

Still, the virtues of mulch are plainly evident.

“The greenness and fertility of my garden are due to vast quantities of mulch, everything from compost to salt hay to seaweed,” Eleanor Perenyi extolled in her garden classic, “Green Thoughts” (Modern Library, 1981).

“To non-organic gardeners, mulch’s primary function is to keep down weeds and conserve moisture in summer; in winter they may use [it] to keep the soil from freezing and heaving around favored perennials. But to gardeners of my persuasion, mulch is much more: It is an organic substance whose benefits extend to the soil itself, improving its structure and enriching its fertility to the point where it needs nothing else. An organically mulched vegetable garden never requires tilling, digging or hoeing, and is scarcely weeded. [Mulch] doesn’t burn or cause sudden spurts of unhealthy growth as artificial fertilizers may – it is long-term in its effects.”

Perenyi was not much in favor of wood chips, seeing them as too expensive when purchased commercially, a “staple of every corporate planting,” and low in nitrogen, requiring the addition of a fertilizer to compensate [more recent research seems to refute that, as you’ll see below]. Still, she was wholly committed to using mulches that were to her liking, “even newspapers and old carpets.”

My qualms about adding so much wood chip mulch to my grounds are assuaged by some online browsing. My search for “composting wood chips” brings me to a collection of web pages produced by Washington State University and composed by an expert I soon recognize as the modern maven of mulch, Linda Chalker-Scott.

In a 2007 newsletter produced by Master Gardener,  Chalker-Scott, who is a Ph.D. , Extension Urban Horticulturist and Associate Professor, and MasterGardener WSU editor at the Puyallup Research and Extension Center, Washington State University Puyallup, explains:

In areas where trees are a dominant feature of the landscape, arborist wood chips represent one of the best mulch choices for trees and shrubs. A 1990 study evaluated the landscape mulch potential of 15 organic materials, including grass clippings, leaves, composts, yard wastes, bark, and wood chips. Wood chips were one of the best performers in terms of moisture retention, temperature moderation, weed control, and sustainability.

“In many urban areas, arborist wood chips are available for free, representing one of the most economically practical choices. Unlike the uniform nature of sawdust and bark mulches, wood chips include bark, wood, and often leaves. The chemical and physical diversity of these materials resists the tendency towards compaction seen in sawdust and bark. Additionally, the materials vary in their size and decomposition rate, creating a more diverse environment that is subsequently colonized by a diverse soil biota. A biologically diverse soil biota is more resistant to environmental disturbance and will in turn support a diverse and healthy plant population.

“Wood chips are considered to be slow decomposers, as their tissues are rich in lignin, suberin, tannins, and other decomposition-resistant, natural compounds. Thus, wood chips supply nutrients slowly to the system; at the same time they absorb significant amounts of water that is slowly released to the soil. It is not surprising that wood chips have been cited as superior mulches for enhanced plant productivity. Wood chips have been especially effective in helping establish trees and native plants in urban and disturbed environments. Arborist wood chips provide incredible weed control in ornamental landscapes. The mechanism(s) by which wood chips prevent weed growth are not fully understood, but probably include light reduction (preventing germination of some seeds and reducing photosynthetic ability of buried leaves), allelopathy (inhibiting seed germination), and reduced nitrogen levels at the soil-mulch interface (reducing seedling survival).

“While there are imported wood mulches available for purchase at nurseries and home improvement centers, they are not as cost-effective as locally produced wood chips, which are often free. In a society where using locally produced materials is increasingly popular as a measure of sustainability, arborist wood chips are a natural choice. Finally, the reuse of plant materials as mulches keeps them out of the landfill—a benefit with both economic and environmental attributes.”

In any event, over a season or so, the wood chips spread across the bare ground are broken down by rot and mold and earthworms to become a deep new layer of biomass that is easily tillable. True, sometimes a layer of chips gets permeated by a web-like tangle of fungus, and I’ve read that decomposing wood chips can suck available nitrogen from the soil underneath and turn the ground more acidic than some plants favor. What’s more, all that wood decomposing does add a measure of carbon dioxide to the atmosphere.

But on balance, a blanket of local, fresh-made chips spread around the walkways and untended areas saves energy all around. It lays the groundwork for healthier plants, especially when combined with compost, which I tuck around the perennials and spread across my vegetable garden and atop the densest patches of my plantings. It all makes my yard that much more of a biomass factory, though I marvel at how all that minced wood reduces to so little. I realize what I’m shoveling is mostly water and air, bound only for a moment of time into bite-size pieces of carbon.

Earlier this week, I turned out the dog for his morning relief just as a cherry-picker and a truck hauling a chipper lumbered past my driveway and stopped two houses down the street. They were there to remove a big old white pine overhanging a neighbor’s house. After watching the driver expertly back the truck and chipper up the narrow drive, I asked if he wanted to dump the chips in my driveway.

Good for him, good for me, as it’s a no-brainer to drive a truck 30 yards down the street rather than 30 minutes to some rural landfill or refuse yard. And sure enough, when I came home at the end of my work day, my driveway was covered with a pile of fresh-cut wood chips wide and deep enough to hide a car.


A freshly dumped load of wood chips nearly fills my driveway.

A freshly dumped load of wood chips nearly fills my driveway.

By now, I’ve got the process down, if not to a science, then a sport. Come Saturday, I am ready to dish. I use a wheelbarrow, a hay pitchfork with four curved tines and an old wide shovel I use to plow snow off my driveway.

I get started by leaning the wheelbarrow sideways into the pile and filling it with chips dragged from the top of the pile with the pitchfork. As the pile reduces, I use the wide-mouth shovel to scoop up from the edges. I know just how many fork-fulls or scoops it takes to fill the wheelbarrow and have a good idea of how best to wield the wheelbarrow around the garden beds to keep from burying an azalea or phlox.

Besides, wood chips – especially this load of light, bright-yellow pine, flecked with minced green – is easy to work with.

I can work my way into a dump-truck-size pile in less than a day, replenishing all of my garden beds along the way. Fill a wheelbarrow, walk it over to a garden bed, tip, then repeat. Every five loads or so I stop to rake the few piles flat across the garden beds and around the buses. It’s my exercise, a chore I relish. A moveable feast of a compost pile.

Just a few wheelbarrows left to spread among my garden beds.

Just a few wheelbarrows left to spread among my garden beds.

Dr. Chalker-Scott’s research findings about compost can be found on a wonderfully informative website produced by the Washington State University Extension called Horticultural Myths, at More of her findings may be found at The Garden Professors blog,

My Pile: Topping Off

Here in southern Connecticut in early December, leaf season has peaked and passed. The yards around town have, mostly, been swept clean of fallen leaves, giving way to the bleaker, bare-bones look of early winter.

Each morning the yellowing blades of grass in my lawn are etched with hoar frost and crinkle underneath my footsteps as I venture out with the dog to walk the property.

My pile, a week ago crowned higher than my head with the last big crush of swept-up leaves and gathered seaweed, continues to settle in upon itself, exhaling nightly as it assumes a more graceful angle of repose. The crystalline morning dew sweeps up the front flank from the cold ground to melt away as wisps of steam vapor waft into the ether from the soggy, saggy top.

My pile is never done. It is, by definition, a work in progress, and I am never done with it. Today, as soon as the morning warms, I will top off my pile with the remaining leftovers from the holiday just past. My pile is more than a match for all that we create and consume.

I read in “Improving Your Soil – a Practical Guide to Soil Management for the Serious Home Gardener” by Keith Reid (Firefly Books, 2014) that “For every 100 pounds of fresh organic material added, a mere 1 to 2 pounds end up as humus.”

I’m fascinated by the disappearing act that is my pile, and Reid has the scientist chops to explain what’s going on underneath the surface:

Every time you mix pea vines or carrot tops into the soil, you unleash a cascade of biological activity. Insects, mites, snails and earthworms begin tearing the plant material into pieces as they eat their fill, creating residues that smaller organisms can access more easily. Fungal hyphae begin growing through the leaves and stems, excreting enzymes that digest the tough cell walls. Bacteria and other microorganisms colonize the exposed surfaces, absorbing the nutrients that have been released for the plants’ growth and activity. All these organisms convert carbohydrates into more organisms, while some is respired as carbon dioxide and returned to the air.

This growing population of fungi, bacteria and other organisms attracts the nematodes and protozoa that graze on this bounty to support their growth. They, in turn, are eaten by other organisms. As these creatures excrete waste products or die, they are cycled through more bacteria and fungi. At each cycle, some of the easily digested organic material is respired and lost, while the most resistant materials gradually accumulate. Eventually, only the toughest material remains – the black substance we know as humus—but it represents just a tiny proportion of what was originally added to the soil.”

To be fair, Reid is ambivalent about the value of composting versus adding raw organic material straight into the soil:

“I am a bit of a skeptic about compost and the suggestion that it is a magical solution to all our garden problems.

“There are lots of advantages to composting. The materials produced through the composting process are much easier to handle and mix with soil … nutrients are stabilized in forms that are slowly released in the soil.

“Composting is essentially accelerated rotting, [and] logic dictates that since it is the fungal hyphae and bacterial slimes produced during decomposition that help create a stable soil structure, there is a greater benefit to having decomposition occur in the soil. With composting, most of the biological activity happens outside the soil environment. But if the choice is between composting your old pea vines and returning them to the soil or leaving them on the curb for the garbage truck, I vote for composting!”

Composting has my vote, and although I “grasscycle” much of my grass clippings and mulch many a fallen leaf back into the ground as I mow, I grow weary of having to sweep and vacuum up all the flecks of such litter I track into my kitchen and onto my carpets. Besides, my life and garden would be much poorer without the ongoing backyard science experience that is my pile.

So I will keep stuffing the ballot box that is my pile with the raw organic material that it likes best and that I have on hand. I have two more buckets full of pungent seaweed gleaned from the nearby seashore; another plump plastic bag of shredded office paper, and a small bucket of scraps from my kitchen.

Topping off my pile Dec 2015.jpg

The bottomless (or topless) pit of my pile, ready to receive more leftovers from the kitchen, office and nearby sea.

I skirt the old wood stockade fence along the backside of my property to check on the bigger metal ash can my neighbors keep outside the back door to their kitchen and find the lady of the house stuffing it full with the last of the Thanksgiving leftovers. She has a spare plastic bag packed with the soggy sheaves of newspaper from their rabbit’s cage; she begins to apologize for her youngest daughter being so neglectful of late in cleaning the hutch, but I am happy to take the load off her hands.

I glance toward the back of their small, fence-in yard to notice a low ridgeline of leaves raked just far enough away from their picnic table to be out of the way. She’s diligent in keeping her front yard tidy, and through the fall has swept up her leaves into piles for me to drag over to my pile with a bed sheet, but has yet to tackle the backyard. She knows that on through the winter I will help finish the task, as my pile is like the bear in the storybook and always wants more.

My gleanings assembled, I take the wide-tined hay pitchfork and, turning it upside down, tease the top of my pile from the center to the edges, releasing billows of steam vapor from the dank mix of whole and chopped leaves. Into this newly formed caldera I scatter the bright white office paper, then chuck the upturned plastic bucket full of kitchen scraps from next door. I gingerly tease the rabbit-hutch mess from its plastic bag, and use the tip of the pitchfork to separate the soggy, urine-soaked newsprint. The value of the bunny’s contributions to my pile far outweigh my squeamishness in handling the mess, but just the same, I cover it up with a thin layer of leaves raked up from the front of my pile.

The buckets of seaweed are next, and I stick the pitchfork into the mix to dredge up a tangle of sand- and shell-flecked rotting lettuce from the sea and sprinkle it across the leaves. I always like to stop to examine the flotsam. There must have been a mass molt among the crabs, for this batch is suffused with their carapaces.

I finish by taking up the four corners of the bedsheet full of damp maple leaves and, stepping up along the top of one of the log walls that frame my pile, drag the sack up and unfurl the groaning load across the top.

My pile, newly suffused with a fresh load of raw organic material, has returned to mounded form, and underneath its new cloak of old leaves, will continue the unseen magic of its transformation into something much less, and much more.

topping off

What looks like a big ol’ pile of dead brown leaves actually conceals a riot of “accelerated rot.”