Gravel Is Great, Just Not Straight on the Ground
If you’ve chosen gravel to denote a space within your yard, don’t just spread it on the grass. Most grass and other plants will grow through the stone, and it will look messy within the year. The same thing goes for areas you’re mulching that might be prone to weeds.
Laying out a weed barrier like the one you see in the photo will keep the unwanted plants from poking through. You can cut x’s into it if you plan to plant shrubs or trees, and the weeds will still be held at bay by the barrier. It will also ensure your gravel doesn’t wash away with a drizzle of rain.