Sheet Composting

This article appeared in 2004 in my St. Petersburg Times gardening column. It is fully relevant now and in all climate zones as a healer and builder and sustainer of rich, living soil. John


Have you ever walked through an old growth forest and felt beneath your feet that rich spongy layer of natural compost accumulated over many human lifetimes? Year after year, a steady rain of falling leaves, bird droppings, pine cones, expired perennials and annuals, fallen fruits and the nutrients dissolved in rain water recreate and revive the soil beneath the green canopy of trees. This life-giving mantle of organic matter is a far cry from the lifeless sprinkling of decorative red bark nuggets, or occasional bag of peat, or a "miraculous" blue chemical fertilizer that many of us have attempted to heal our soil with. So how can we bring Nature’s soil enriching methods into our gardens?

"Sheet composting"! Many of us have never gotten around to conventional composting because we don’t have a compost bin, or aren’t thrilled by the thought of having to turn the compost pile monthly, or spreading the finished product all over the far reaches of our landscape only to start all over again. Sheet composting eliminates those hassles by simply spreading compost-forming materials all over one’s gardens in a "sheet" of compost that builds up and decays and feeds the soil directly and steadily. It is an easy way of duplicating the forest’s method of constant soil improvement. Just think, with every good rain or deep watering, that sheet of organic matter leaches into the soil beneath it a life-giving broth of nutrients and beneficial bacteria and fungi. What was once funky lifeless dirt soon is rich humusy soil teeming with earthworms and healthy garden plants, all for free!

Recycling has progressed from being a "hippie fringe behavior" to a respectable mainstream habit our society embraces more and more in an effort to protect an environment under daily assault by a burgeoning human population. "Sheet composting" allows each of us to keep valuable organic matter out of landfills by healing our soil with an intriguing array of freebies. Why buy expensive bags of lifeless perky red mulches made from killed trees once you start noticing the boxes of cabbage leaves and corn husks your grocer will give you, or the kitchen scraps you’ve always sent down the disposal? Duplicate that forest and mulch your veggie or flower garden with chopped up bush trimmings and pesticide-free grass clippings, or leaves covered up with the horse manure the neighborhood stall pays to have hauled away. Buzz each evening’s kitchen scraps in the blender with water and toss that nutrient-rich slurry onto your sheet compost to feed the soil without attracting raccoons and opossums with intact table scraps. Use cheap clay cat litter, or plain garden soil or tree grindings mulch instead of the anti-bacterial clumping stuff in the litter box and toss that nitrogen rich mixture into the rose garden. Stop at your local coffee shop once a week and bring home big bags of coffee grounds and sprinkle them onto that sheet of compost forming steadily in your landscape beds. You get the idea…..if it will rot and it is free, bring it home and sheet compost with it!

Of course, esthetics are important, and who wants to gaze at a flower bed littered with decaying fruit, cat litter and corn cobs…hardly the cover of "Better Homes and Gardens"! Just sprinkle a more attractive mulch material over your newest "deposits" to your soil’s fertility account, like tree chips mulch, pine needles, raked leaves, or a bale of hay shredded quickly by hand…one $5 bale will easily cover a 10 foot by 10 foot area with a pleasing blond mulch hiding all those decaying treasures while minimizing flies.

As your sheet of compost becomes a continuous mantle over all your gardens, you’ll notice that the soil stays damp and dark and earthwormy between rains and waterings, and that your plants are perking up big time. You’ll notice too that your deposits to the garbage man have shrunk, and that you’ve started coveting neighbors’ yard waste… "Hey man, can I have your pine needles?" "What are you going to do with those bags of leaves?" You’ll also notice that your gardens need less and less fertilizer. Why? Compost is the gold standard of soil amendments. A light sprinkling of fish meal each spring and fall all over the sheet compost will insure perfect plant nutrition. If your soil is acid, a light sprinkling of dolomite or garden limestone each spring will keep your soil "sweet" while supplying vital calcium and magnesium. While ordinary mulch primarily keeps soil moist and cool, modifying it into sheet compost turns it into a continuous Thanksgiving Day feast for your gardens. And a thick damp mulch will help slowly acidify alkaline soils.

Poor soil causes most of our ongoing gardening frustrations, and is crying out for us to imitate Nature’s ways. Sheet composting is a solution for those woes, so let’s use this simple mulching method to heal our soil, our budgets, and a burdened environment.