Leave your leaves on the ground this fall, says the Nature Conservancy of Canada.
Andrew Holland National Media Relations Director says a layer or two of leaves on the ground, can help certain insects with a layer of warmth.

Holland suggests this is important because we have fewer insects than before and by treating your lawn as it’s own ecosystem, it helps insects, pollinators and butterflies that are trying to make it through our tough winter climate. Holland says this is especially needed now as North America have lost 2.9 billion birds over the last 50 years, due to a variety of factors. By keeping a layer of leaves on your lawn for insects, it provides a significant food source for birds.

Holland says having large pile of leaves is not beneficial as it could smother your lawn or damage the turf. Holland adds leaves break down pretty quickly, the same as they would in a forest. A layer or two of leaf litter, he says, even if they are mulched, can act as a free fertilizer because it breaks down leaves and puts nutrients into the soil, and could save some money come spring time.

Holland suggests an alternative is to move leaves into flowerbeds, gardens or underneath shrubs, to protect plant roots during the winter.