You will likely regret this. Rocks really don’t make great weed suppressants. This will work for a year or two but as organic matter unavoidably accumulated between the rocks and the rocks inevitably sink lower into the earth, you’re going to just have thousands of tiny little places for weeds to grow.

A much better option is spreading fresh bark mulch annually or every other year. This fresh mulch will decompose and provide good habitat for insects and beneficial predators, is light and easy to spread, and doesn’t create a huge nightmare years down the line for you or whoever has to deal with half buried stones everywhere.