Describe your suggestion:
When you apply certain items, the respective overlay appears on the targeted block.

Seeds: Block looks like grass is growing on it.
Mushroom (Red or Brown): Block looks like mycelium is growing on it.
Wheat: Block looks covered in thatch.
Vines: Block looks overgrown, as if nature has reclaimed it.
String: Block looks like it has cobwebs

Additional context:

Grass:
Snow:
Vines:
Webs:
Hay/Thatch:
Mycelium: