Dried, dead leaves contain stored energy, the sun’s energy. Put them on or in the soil, as I have been doing, and they release their energy to support the growth and activity of fungi, earthworms and other soil organisms. Mostly, these are friendly creatures, and nurturing them allows them to thwart unfriendly organisms, such as those causing some plant diseases.
Besides disease prevention, when leaves are gobbled up by soil organisms, the nutrients in them are being released. Think of all those minerals taken in by a tree’s deep roots. Leaves are, pound for pound, about as rich in minerals as is manure.
NOT FOR EVERYWHERE. Of course, spreading leaves over the ground or just leaving them there in the first place is not an option for every site.
I have spread leaves over a hayfield in which I’ve planted chestnut trees. In coming years, these trees will shade out the grass; I’m just helping the ground become the leaf-blanketed forest floor it will eventually turn into.
Beneath a row of dwarf apple trees, a leafy mulch keeps weeds from growing and stealing nutrients and water from my small trees.
And no need to rake up all the leaves from a manicured lawn: A mulching mower grinds them up to let enough grass peek through to thrive.
If leaves form such a thick blanket that raking is necessary, don’t bag them until you’ve spread all you can under your shrubs and trees, and over your flower beds. Save yourself effort and do something for the plants: At the very least, leave leaves where they drop.
LEAVES PLUS TIME EQUALS COMPOST. Still drowning in leaves? Hold off a bit longer before you pack them into trash bags. Consider packing the leaves into a dense pile for composting. Leaves make excellent, weed-free compost.
In a rush? Then mix in some manure, sprinklings of soybean meal or other materials rich in nitrogen.
By next year at this time, most of the leaves you spread around or piled up will have either settled or evanesced into thin air, becoming mostly carbon dioxide and water. A significant but small portion will endure in the soil, having been transformed to humus, which, provides long-term benefit to the soil, aerating sticky clays and helping sands hold water for plant use.
Roses, rhododendrons, lawns – almost all plants, in fact – appreciate any leaves left or applied around their “feet.”.