While we are getting ready to replace our gravel with concrete, the previous owner place plastic under the gravel. It works well, with one observation to improve it. He should have provide a greater lap of the plastic sheets, possibly even bonding them with an adhesive.

While there are few weeds in the middle of the plastic the weed that are there appear to be coming up between the sheets of plastic.

With the plastic you will have to be careful during future maintenance as if torn you are back to the original problem.