What happens if you just leave them

Leaving leaves is sometimes good advice, and it gets repeated in places where it does not apply. A light scatter mulched into the lawn genuinely feeds it. That is not what a wooded Ocean County lot produces. What a continuous oak canopy drops is a mat, and a mat behaves differently. It blocks light, holds moisture against the crown through a wet coastal winter, and comes off in spring over grass that has gone pale, thin or slimy underneath. On the shaded side of a house it is worse, because nothing there dries out. The practical line is whether you can still see grass through it. If you can, mulching it in is reasonable. If the lawn has disappeared, it needs to come off — and it needs to come off before it packs down rather than in March when it already has. Beds are the exception in the other direction: leaf cover over a bed through winter is useful, which is why hand-clearing beds is a different job from clearing lawn, and priced as one.