Landscape Rock

Depending on the size of the river rock and the density of your soil, add woven landscape fabric or sand under river rock. The extra layer will ensure your river rock sits evenly and doesn't create puddles or uneven areas throughout the design. In some cases, nothing is necessary beneath river rock, but be sure to speak with a landscaper to keep your landscaping looking sharp.

If you hire a professional landscaper, you could expect to pay between $90 and $660 to install three cubic yards of river rock. (That’s based on the average river rock installation cost of $30 to $220 per cubic yard.) However, the exact price depends on the kind of river rock you choose. Crushed limestone and riprap are some of the more affordable options, while boulders and Arizona river rock are pricier.

Rocks are less likely to attract snakes and other critters because their prey (termites, ticks, and other insects) don’t usually inhabit this environment. However, if you have placed together rocks with large spaces in between or near a source of water, you may find a snake or an occasional chipmunk seeking shelter.

The best size rock for your landscaping depends on the design, as different boulders serve different purposes. If you want to group boulders to create a natural-looking cluster, you’ll need a range of sizes. Otherwise, here are some suggestions:

• Small boulders (smaller than 12 inches across): Best for landscape edging and fire pits 

• Medium boulders (12–24 inches): Best for retaining walls and water features

• Large boulders (more than 24 inches): Best as standalone landscaping features, steps, or walkways.

Of course, you can mix and match sizes to create a unique display.