Early Morning Ageratum

I was out poking around the garden early in the morning and saw these little blue ageratum that must have seeded themselves last year and just now decided to show up. What really caught my eye was the shadows on the rocks. I dashed in grabbed my paint stuff --perched precariously on another rock and started. I think I had five whole minutes before those shadows dissapeared. Plein air work is so chancey. Difficult for a control freak like me. I notice that my outdoor paintings ( usually garden scenes ) tend to be much darker in value then the still lifes. Interesting.
I have a french easel I've never used. When I do these garden studies I wonder that I don't do more outdoor work.