If you’re going to put a one-foot boulder next to a one-gallon plant; next spring you’re going to be wondering where the boulder went because the plant will have grown over it. So take that into account, the relationship versus the size of the boulder.
Average Boulder Weights by Size
A one-foot boulder can probably weigh 80 to 100 pounds, a two-foot boulder could be 300 to 450, a three-foot boulder can weigh anywhere from 1,200 all the way up to 1,800 depending on length, width, and height. We’ve included our boulder weights chart to give you a better idea of boulder weights by size.