Leave Those Leaves!
by Betsy Washington
Falling temperatures and shorter days herald the arrival and breathtaking beauty off our annual fall foliage display. This spectacle coincides with the annual ritual of removing fallen leaves from our lawns and gardens. Lazy, golden fall days are suddenly filled with a cacophony of leaf blowers, whining from sun up until sundown. Vast piles of leaves are hauled to our streets to await an army of county trucks that haul them away, all amid clouds of dust and exhaust fumes. Ironically, next spring we will rush to garden centers and county recycling and waste centers and buy bags of prepackaged fertilizers or soil amendments and truckloads of mulch, to be spread by expensive lawn crews and laborers. Whew! It makes me feel tired and poor just thinking about it!
But wait! Isn’t there a simpler and better way? Before the days of pre-packaged amendments and fertilizers, leaves were left where they fell as a natural mulch and soil amendment. Leaves were raked under trees and shrubs to decompose and enrich the soil. Through the process of decomposition, thousands of beneficial soil borne microorganisms began the process of breaking down the leaves and turning them into rich, dark leaf mold – nature’s own fertilizer. With annual additions of leaf mold each fall, even the heaviest clay soils became rich and moisture retentive, teeming with life. The naturally amended soil acted like a sponge, holding a wealth of water and nutrients readily available to plants. Plants living in soils rich in leaf mold and microorganisms are healthier and live longer. And no wonder – scientists have discovered that soils rich in organic matter, contain a broad array of natural antibiotic and fungicidal compounds that prevent a host of plant diseases and pests. It’s no small wonder that plants in our undisturbed forests and natural areas live for hundreds and even thousands of years, with few outbreaks of serious diseases or pests. Compare this to the life expectancy of trees in our own gardens, which are measured in decades, not centuries.
“Biomimicry” is one of the eight principals of sustainable design. By leaving fallen leaves to decompose in our gardens, we are mimicking the natural processes that have sustained life on earth for millions of years. So this fall, why don’t you follow nature’s example? Leave your leaves as a natural mulch under trees and shrubs. If nature’s bounty of leaves threatens to completely engulf you lawn and garden, give nature a hand, and try running your lawn mower back and forth over the leaves, breaking them into small pieces. Simply leave these small pieces in the lawn and reduce your fertilizing needs by over 30%, or use a mulching or bagging attachment on your lawnmower, and collect this fine mulch to spread around your trees and shrubs. A weekly mowing of leaves, will take care of most of your leaf surplus, and save energy and money by avoiding the backbreaking bagging and hauling of leaves to our landfills and waste centers. You can also easily rake your large leaf piles into a chipper-spreader turning them into a fine, nutrient rich mulch to use in your garden borders. This is much easier that bagging them or raking large piles to the curb.
The one time when leaving your leaves is OK is if you’re growing only shrubs and trees, no perennials, bulbs, groundcovers or lawn, AND you don’t have either wood chip mulch or landscape fabric forming a barrier between the leaves and the soil. The shrubs and trees won’t mind the leaves forming a tight mat on the soil since their stems stay above ground, and the leaves can break down slowly and improve the soil.
- And lastly, matted-down leaves on the lawn or on groundcovers can cause dramatic bare spots in a matter of weeks. In one garden I know of where the natural look is preferred, a drift of leaves killed all of the foliage on the Blue Star Creeper groundcover that was acting as a small-space lawn in just a couple of weeks. Then weeds put up a fight to take the space over while we coddled the Blue Star Creeper back to life!