Glorious decay

The garden season is closing out and cashing in, and frost is nipping at our heels as we tend to the cole crops we expect to nurture through the cold months. Deciduous leaves have begun to litter the lawn. It is that time again when a gardener’s heart turns to the glories of decay. Ashes to ashes, dust to dust, complex carbohydrates into their constituent molecular precursors and all that jazz.

But enough daydreaming. Sure, the biosphere has been chugging along just fine for hundreds of millions of years, reusing nutrients, rotting and rising from the dead again. But in a garden, we harness natural forces to produce local abundance. The shortcut is to dose the ground with chemical forms of the essential plant nutrients nitrogen, potassium and phosphorus — respectively, by their symbols, N, K and P, — and to adjust soil pH (most often with lime).

The immediate problem with chemical gardening is that, although it provides critical plant nutrients in easily assimilated forms, it doesn’t replenish myriad trace minerals or nurture the soil. Worms and grubs, for instance, don’t subsist on NKP fertilizers. When worms and grubs disappear, moles don’t come around much anymore. Without worms and moles to stir up the soil, water doesn’t penetrate very easily, so it runs off instead of soaking in. When water runs off, it washes away some of the light, fluffy topsoil and floats off plant matter, bugs and worm poop. Before you know it, you’ve got a desert on your hands — and you don’t want to go there.

So, wise gardeners (that is, those who agree with me) feed the soil instead of giving plants a quick fix. I like to think of this as offering cultivars a natural high instead of getting them hooked on the hard stuff. Plants raised on a strict diet of chemical NKP fertilizer are like kids raised on candy bars, greaseburgers and soft drinks — they may get tall and have all the right parts, but they won’t ever be really healthy. What soil likes for breakfast is basically the same thing that earthworms and bacteria like for breakfast — dead stuff and poop. The more dead stuff and poop you add to your garden, the happier your plants will be.

The dead stuff we usually have most of is plant parts. (Dead animal parts are best buried deep enough that the neighbor’s dog won’t unearth them.) The easiest way to use dead stuff as fertilizer is to spread it on your garden. This is mulching, and it works best to spread dead plants and manure together because animal waste is high in nitrogen, while plant matter tends to be higher in potassium and phosphorus.

Not all plant matter is the same. Grass is relatively high in nitrogen and breaks down quickly. (That’s why a mound of grass clippings gets really hot in the middle.) Oak leaves are relatively low in nitrogen and left alone may take a few seasons to decompose. Physical differences also affect the decomposition rate. Grass clippings tend to clump, and fallen oak leaves tend to layer. Both shed water, which can slow combustion. Plant stems may take a very long time to decay. And between garden residue and fallen leaves, you may have a whole lot more plant matter than you want to look at spread out and blowing around your yard all winter.

What to do? Compost. Composting is simply an organized method of mixing dead stuff and poop to catalyze the release of trapped nutrients. The more mixed and diverse your mixture, the quicker the release. Different experts can make it sound tricky or mystical, with recipes and warnings, but that’s not the way real life works.

The way real life works is that you have been dumping your kitchen scraps, weeds and grass clippings in a pile or bin all summer. What you’ve got is a slowly rotting pile of dead stuff without much poop. Trouble is, if you just pile poop on top, it will become a dead-stuff sandwich, with veggies between a slice of dirt and a slice of dung. What you really want is a stew.

You’ll need an enclosure — if you’ve been using one through the summer, you can lift it off the pile and reuse it. (I like to use four discarded wood pallets tied at the corners with nylon rope or wire. But any topless/bottomless enclosure with some side vents will do.)

Put a crosshatching of finger-size branches in the bottom, a few inches deep. This helps ensure aeration because decayed organisms breathe oxygen just like most of our other animate cousins on earth. A piece of 2-by-4 pipe a little taller than the bin is a nice addition — stand it in the center of the bin as you fill it. Then throw in a few inches of deciduous leaves. Add a few inches of summer’s dead stuff, and top it off with an inch of poop. If you haven’t got poop, you can use nitrogen fertilizer, just sprinkle some on like jimmies on ice cream. Poop is better because it contains much more than just nitrogen, but nitrogen is essential to the process. Now add an inch of dirt. Keep repeating the layers, as if you’re building a Dagwood sandwich with the pipe as a toothpick, until the bin is full — or until you’re out of dead stuff, poop or time.

If the dead stuff is pretty dry, it doesn’t hurt to water the pile now and again as it grows. When you finish, top it off with a few inches of dirt, sloped so it drains to the middle. Finally, wiggle the toothpick around, and pull it out. The resulting hole will let air and water circulate in the stack. Patient souls are finished at this point — until some time next year when the resulting compost is wheelbarrowed to the garden. The pile will heat up, steam more than the grass pile on cold mornings and gradually sink as decay has its way with the plant structures. To speed the process, less patient souls can turn the pile after a couple of months.

My method is to add two pallets to form a second attached bin — like a miniature horse stall — and remove the front pallet from the first pile. Then I pitchfork the contents into the new stall with the pipe in the middle. This time around you are mixing it up (no layering), though if a lot of the plant matter seems not rotten yet, adding some poop will hurry things along. Cap it with dirt again and pull out the pipe.

Come spring, you can spread the rich, rotten result anywhere you want plants to grow, use it for side-dressing around perennials and shrubs, or screen it and use it for potting soil. Your plants and earthworms will love you, and your neighbors will be jealous.