Don’t bother bagging your fallen leaves. Your yard (and insects) will thank you

As the last leaves fall in the Philadelphia region, environmental experts say: Leave them where they are.

It’s actually better for your yard and local ecosystem if you don’t rake and bag fallen leaves.

“Leaves have the exact combination of nutrients that lawns need to be green and healthy,” said Mike Weilbacher, executive director of the Schuylkill Center for Environmental Education. “Many people fastidiously pick up every leaf that’s on their lawn and then replace it with fertilizer that has the exact same combination of nutrients that leaves have.”

As leaves decompose, they act as a natural fertilizer for your lawn, putting nutrients — like carbon, nitrogen, and phosphorus — back into the soil.

If you’re trying to maintain a grassy lawn, don’t leave the leaves in a thick layer. Shred them by running them over with a lawn mower. You can also use fallen leaves in compost.

“You just can’t leave like a mat of leaves on your lawn because it’ll get wet and it might hurt the grass,” Weilbacher said. “So actually what you want is to mulch those leaves.”

But be sure to leave some “messy corners,” or piles of whole leaves around the edges, Weilbacher said. Such a pile becomes an important habitat for wildlife like amphibians or overwintering insects, including ladybugs, butterflies, and native bees.

“Every species of moth, beetle, fly, everybody — they’re all in one phase of the lifecycle, and many of them are in the leaf litter waiting to hibernate,” Weilbacher said.

Even if you’re not a fan of bugs, they’re key to local ecosystems.

“Bugs are one of the little things that hold up the entire world,” Weilbacher said. “We actually need them to pollinate the trees and wildflowers and shrubs that many of us love to have.”

Another bonus to leaving your leaves in your yard: It keeps them out of the landfill.