Harbor Freight sell's some decent brown canvas tarps that I like way better than blue tarps . A little more in costs , but over time , they last a lot longer . I had a large one for replacement cover on one of those 20' x 12' hoop huts . Lasted for the 5 years that it was on there , then took entire hut down . Gave away the steel for hut but kept the tarp and have since cut it down into smaller pieces for other projects . Have had pretty good success in putting new grommet's in the canvas and having them hold without ripping out the tarp even more .
Anything I cover , I don't let the tarp go all the way to the ground , thus it still gets air circulation under it but keeps off the sun and inclement weather .
Fred H.