Hello Art Painter and welcome to the AR forums,
Originally Posted by art painter
Unfortunately, the "smoothing" feature is only available within the new ArtRage 3 (for the Ink Pen and Precise Pencil). You may want to look into upgrading though, because I think the "Sticker Spray" tool would be something you might have an interest in as well. With the Pro version you'd be able to create a sticker (or use one of the sets that come with the program) to make fields of grass fairly easily. I've attached an image displaying some of the types that come with AR3 already. Using the Stickers with the Sticker Spray tool, they act like a brush.
Nothing is easy to the unwilling.