Why leave leaves?

Fallen autumn leaves provide many benefits to soil and wildlife. Leaves protect soil from compaction and erosion from rain, suppress weeds, improve the soil structure and increase soil fertility as they decompose.

Leaving leaves where they fall, or moving them onto garden beds, provides habitat and food for wildlife and beneficial over-wintering insects. Beetles and bumblebees depend on leaves for protection from the cold. Depending on the species, butterflies and moths spend the winter as eggs, caterpillars, pupae or adults in leaves that are attached to trees or have fallen to the ground.

For more information: https://xerces.org/blog/leave-leaves-to-benefit-wildlife

When to leave leaves

If you have native or ornamental broadleaf trees like maples and oaks, leave the leaves in place, to gain full benefit of this natural mulch. Move them onto garden beds if preferred.

When not to leave leaves

Fruit trees in the Pacific Northwest are susceptible to fungi, bacteria and insect infestations. These pests can overwinter on leaves, in the soil, and in the fruit. To avoid infestations, rake up all leaves and fruit and dispose of them. Alternatively, to return these nutrients to the soil, compost the leaves and fruit and apply in 2-3 years. The temperature in compost piles must rise to 130-135 degrees to ensure that weed seeds and pathogens are killed. https://today.oregonstate.edu/news/answers-three-common-compost-problems

Read about other fall gardening tasks https://today.oregonstate.edu/news/take-one-more-go-garden-retiring-winter

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Click here for a printable pdf of this article. Written by Carole Hardy  August 2024. Photo courtesy Pixabay.