In general, these pages take 3 days for every two, when the weather is dry enough to allow my pages to dry quickly and when I'm not juggling other obligations. The longest batch was when I was working on 4 pages at once- two regular pages and a double page spread taped down to my largest lapboard. Juggling that many pages can be a bit overwhelming, but fortunately, all four shared clothing/people/ and three shared a basic color scheme, so much of the time, I was able to apply color universally.
Believe it or not (you should believe it), I actually struggle with rendering larger amounts of grass. I've learned that when pulled out (like on the first page) you should apply strokes sparingly, beginning with your lightest color and occasionally adding darker shades. You should lean toward the under-rendering side when it comes to pulled out shots of grass. The opposite seems to be true for zoomed in. Yes, you're probably still working light to dark (I always work light to dark anyway, so maybe I'm just backwards), but you don't want to under render. I had difficulty pulling the amount of detail I needed in watercolor alone, so I really relied on my Caran d'Ache pencil colors and some watercolor pencils to do the trick. The Caran d'Ache pencils can be blended out a bit with water, better marrying the watercolor and the pencil color on the piece.