Drain rock and other chunky crushed gravels over three-quarters
inch are useful in areas where you want quick drainage, such as in French drains, driveways or around raised beds. As with other crushed rock, the jagged edges help the gravel lock together to form a stable surface, but the gaps between stones allow water to easily flow through. Drain rock and other types of large crushed gravel can be found in light and dark gray and sandy tones, as well as reddish browns.
Note: Drain rock is different from — but easily confused with — base rock. Base rock is a recycled product composed of three-quarters-inch crushed concrete mixed with rock fines and is used underneath foundations, pathways, patios and driveways, not generally as a finishing material.
Cost: Drain rock is sold by the bag for about $3 or by the ton for about $60.