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 leaves give of antinutrients which kill the grass. Also, leaves block out light completely, whereas snow let’s lights through.

Answer 2

If they’re sitting on the same pile for ages, this will first of all, restrict oxygen and sunlight to specified patch.

Second of all, the nutrients from the pile will scorch the ground underneath as it’s too concentrated!

Answer 3

The grass underneath dies from lack of sun.

Snow is mostly air and very light permeable.

I had a tabletennis table on my lawn one whole summer and all the grass in the shadow underneath was completely gone, while the one we were trampling while playing was doing fine.

Answer 4

Snow is white and your plant friends will still see the light and be able to breath, but they are sleeping now, so it’s not a big deal anyway.

Answer 5

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).