a small leaf pile will destroy the grass underneath it quickly, but an even thicker snow pile that lasts for months throughout the winter seems to have no effect. Why?

Question

Editing just to say thanks to everyone who has contributed. The responses make perfect sense!

In: Biology

Answer 1

The moisture buildup, warmth, and lack of airflow kills the grass. Basically starts a mini-compost pile. Look up what happens when you cover soil with cardboard sheets.

[https://en.wikipedia.org/wiki/Sheet_mulching](https://en.wikipedia.org/wiki/Sheet_mulching)

I don’t agree with other comments here about leaves being acidic or lack of nitrogen in the leaves. It’s not like grass will die without a steady stream of organic N being fed to it, and composting leaves typically don’t have any substantial effect on soil pH (and the top leaves don’t decompose fast enough to have any effect at all).