A game of inches

Although I garden in Climate Zone 5B here in eastern Massachusetts, I got a reminder this week that conditions vary in different areas of my yard. The first frost brought an opportunity to observe small differences in temperature between areas as close as inches apart.

            Two pots of wax begonias (Begonia x benariensis ‘Big Red’) next to the front steps offered a striking demonstration of a microclimate, a small area with climate conditions different from its surroundings. The leaves on stems closest to the house stayed green when the night temperature dipped below freezing.

Frost blackened the leaves on stems just inches away on the other side of the large pots. The leaves that died were farther from the warmth radiated by the house’s foundation. 

Before the frost

Leaves farther from the house blackened and melted in the frost

I inadvertently demonstrated another source of radiant heat by leaving a full watering can next to one of the pots. It too absorbed heat during the day and radiated it at night, protecting nearby foliage from frost kill.

The water in the watering can protected the leaves on the left

            My first introduction to microclimates in my garden came when I planted maidenhair fern (Adiantum pedatum). Of three ferns I planted, two dwindled and died and one flourished prodigiously. It’s still with me twenty years later and has gradually produced a small colony. Apparently I’d been lucky enough to plant it in just the right place, on the eastern side of a tall white pine (Pinus strobus) and shaded from western sun by a yew (Taxus x media) and some hulking Catawba rhododendrons (Rhododendron catawbiense) inherited from previous owners.

Maidenhair fern colony in May

            I can’t claim credit for the fern’s success. It was only by chance that I planted it where I did. I can guess that it’s enjoying the right amount of water gently delivered as the pine catches rain on its needles. I knew maidenhair fern was a shade lover—that’s why I bought it. It must also like being out of the wind, sheltered from our prevailing west winds by the shrubs, but with less turbulence than a solid fence or wall would cause.

            The fern colony sits on a gentle slope that runs from the base of the pine to the lawn to its east. That must allow cold air to flow past it to the lawn a few inches below (interesting to know that cold air drains downhill, like water). The ferns are growing under a deep insulating blanket of pine needles and deciduous leaf mulch, which keeps soil moisture and temperature relatively steady.

This week the ferns are enjoying a fresh layer of pine needles

            It’s testament to the breeders’ art that the wax begonias bloomed consistently from May until late October. Unlike the maidenhair fern, they were flexible about accepting the hotter, drier conditions I provided. Now I’ll see if I can root one of the stems indoors and keep it going in yet another microclimate, next to a cold west-facing window in a heated room.

Compost by the barrel

After my disappointing experience with a commercial plastic compost bin, I was tempted to give up on closed composters. The plastic bin didn’t produce any usable compost, and it attracted an unknown animal that easily chewed its way through the side.

            Searching for advice on line, I learned that plastic bins sitting on the ground were well known to attract animals. I looked into more expensive bins, some standing on legs that kept them off the ground and enabled spinning them to turn the compost. I didn’t feel like spending a lot on another possibly ineffective commercial product.  

            I remembered that I did have two aluminum garbage cans full of bird seed standing a few feet from the plastic compost bin, their lids secured with bricks. In five years no animal had managed to penetrate those. And they were round. Maybe metal barrels could be modified to serve my composting purpose, and maybe I could even turn the compost by rolling them.

            In April 2013, I started my experiment with garbage can composting. I bought a small barrel with a tight-fitting lid for about $25 at the local hardware store. An obliging staff member punched half-inch holes in the bottom and sides for ventilation.

Through that summer I dumped in kitchen scraps, adding some soil and finished compost that I hoped would inoculate the waste with hungry microbes.

            This weekend, two and a half years later, I harvested some recognizable compost from my first two trash-can batches. In both barrels, the materials I’d added had shrunk from filling the barrel to the top to occupying about a quarter of its volume. 

This is what the finished compost looked like. Newspaper I used to line the kitchen bucket didn't decompose but was easily extracted.

The finished product was black and seemed fulling decomposed, with no recognizable food bits. I dumped one barrel’s contents in the vegetable bed and another in a perennial border. 

            Why did my garbage can composters work better than the plastic one? They kept animals out, of course. I also think adding soil and compost helped them along. I’d learned my lesson and left out paper shreds, torn-up cardboard from take-out food containers, and fall leaves, all of which had proven to be too slow to decompose in a closed bin, although they worked fine when incorporated into open compost piles. I gave the barrels’ contents one to two years to decompose after adding the last deposit of food scraps, much longer than the sixty to ninety days predicted by the manufacturers of commercial bins.

            I also think rolling the cans occasionally probably aided the decomposition process. I had tried to mix the contents of the plastic bin but found the mechanics completely wrong—because of its diameter and height, about 2.5 by 3 feet, I couldn’t dig inside the bin with a small spade, and the material was too heavy and solid to stir with a stout stick.

            I recommend aluminum garbage cans as effective, inexpensive, and trouble-free closed composters. If you’re haunted by coyotes or vexed by relentless racoons, give it a try. 

The circle of life--from rotten food scraps to compost to New England asters in the garden

It seemed like a good idea at the time

             Four years ago when coyotes started eating small pets in our town, I launched my misadventure with a plastic closed composter. My advice: don’t waste your money on this type of bin.

            My motive was altruistic. Wildlife officials pointed out that coyotes are omnivores, quite willing to snack on carrot tops or apple cores on open compost piles. I didn’t want to invite predators to my block by putting out a coyote smorgasbord of fruit and vegetables. 

On the prowl for watermelon rinds

            In November 2011 I ordered a black plastic bin recommended by a Master Gardener I’d consulted. It was a wide, bottomless cylinder about 3 feet tall, tapering slightly toward the top, equipped with numerous air vents and a locking lid. 

My compost bin was not unlike this one

Throughout that mild winter, I dropped plant waste from the kitchen into the bin, covering the scraps with a layer of dry leaves or paper shreds to provide carbon and to keep the compost from being too wet.

            As soon as the weather warmed up that spring, something chewed a hole through the back of the plastic bin starting at one of the ventilation slits. The hole gradually enlarged to a rough-edged oval around 2 by 3 inches. So now I was feeding a small animal—could it be a chipmunk or a rat?   

I never saw the animal that gnawed a hole in the bin

            I tried to block the hole by fitting a broken flower pot against it inside the bin.  The intruder just enlarged the opening.  Meanwhile, the rate of decomposition inside the bin was unimpressive.  The top level of scraps gradually dropped, indicating some progress (or prodigious work by rodents), but I certainly wasn’t seeing any “black gold.”  After eighteen months with no apparent compost developing, I gave up and stopped adding to the bin.

            Two years after I’d started, I lifted the black cylinder off the pile, revealing an uninspiring mound of hard half-made compost studded with undecomposed egg shells. I pulled out the egg shells and buried them in the nearby open compost pile. I plunged my spade into the remaining lump, and that’s when I realized that the bottom 3 inches was a mat of roots. I should have lined the bottom of the bin with landscape fabric. 

            So after two years, I had about a half bushel of black, dry, partially decomposed food waste.  It didn’t look like it would attract animals, so I chopped it up and dumped it in a corner of the vegetable bed, hoping it would do some good next year.

            This was a far cry from bin manufacturers’ bold promises of finished compost in sixty days!  I threw the smaller parts of the plastic bin in the trash but couldn’t fit in the main cylinder. That would have to wait until the Public Works Department came to pick up large items.  Even getting rid of the bin was inconvenient. At least I hadn’t attracted any coyotes.

            Tune in next week for a cheaper way to keep food waste away from animals.