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.

Consider starting a compost pile. This can be as easy as creating a large pile of leaves in an out of the way place. Nature will take care of the rest – in a year or two you will have your own supply of rich, crumbly leaf mold. You can hasten the process by chopping the leaves first with your lawnmower or chipper-shredder, and by layering green material such as leafy food wastes, grass clippings, or alphalfa meal between layers of leaves and turning the pile once or twice and keeping it moist. Either way, your garden will be far healthier and will shrug off droughts and climbing temperatures without the need for extra watering, and your soils will be naturally rich with little if any need for extra fertilizers that risk the health of our lake. And you will save money and help in greening the planet, all by following nature’s example. Sustainable indeed!

Other Fall Gardening Tips:
Leave seed heads of perennials like asters, coneflowers, sedums, and grasses until late winter. They provide winter structure to the garden and are beautiful when covered with frost and snow. They also provide seeds for overwintering birds, and shelter for beneficial insects. Avoid pruning plants during the mild days of fall, when pruning can encourage tender new growth that is sensitive to freezing and winter damage. Wait until after several hard frosts when plants have stopped active growth.

Prune spring blooming shrubs such as forsythia and azaleas after they bloom in late spring. Spring blooming plants typically bloom on “old” wood, and you will be pruning off the flowers buds if you prune this fall or winter. This also applies to some summer blooming plants like Bigleaf Hydrangeas, that are best pruned just after they finish blooming in summer.

Rake up and destroy diseased leaves from plants that exhibited fungal diseases like powdery mildew (some peonies, crape myrtles, lilacs), rust (fruit trees, hawthorns), or blackspot (roses). This will help remove disease spores that would otherwise overwinter in debris ready to reinfect new growth next spring.

Water evergreen plants regularly during dry spells this fall. Most winter injury and plant loss occurs after summers and falls with prolonged droughts. Continue to water prized evergreens during mild spells through winter.