Yes except if the grass portion is rather small.
I tried a 7000 pieces area, which I suppose is small, and did as above.
I’ve never had problems with rocks, trees or gravel and I’ve already rendered several times with much bigger surfaces.
I think it could be related to the update I did from Skp 2017 to Skp 2018.
Never had problem before that but who’s having problems between SketchUp, Vray and Skatter?