If you want to keep those cheap styrofoam tombstones from blowing away, stick two bamboo skewers halfway into the base of them . They go about 10 inches into the soil and
JOYIN 17" Halloween Foam RIP Graveyard Tombstones (5 Pack), Yard Sign Headstone Decorations and 12 Bonus Metal Stakes for Halloween Yard Outdoor Indoor Decorations - Walmart.com