The Aspen Trees - Oil Painting

I am trying to create an oil painting of a photo taken in Aspen, Colorado of the beautiful Aspen trees.  In fact, while in Colorado, I got lots of photos to use as references for some terrific paintings.  However, this first painting is giving me a bit of trouble.  I should have primed the canvas first, or painted in a little blue sky to peak through the trees.  The photo that I am using as a reference is above.  Any suggestions???  No, you do not want to see the canvas just yet.  I just completed a portrait of a co-worker and her two dogs.  Unfortunately for her, the dogs look better than she does.  I mean, she is a beautiful girl, but I did a better job of the cute little doggies.  That is my deal, animals..according to Matthew and David, at least.  They say that I am better at painting animals.  I think they are right.  Should stick to panda bears, dogs and cats, maybe.    Fiddle-dee-dee.  I placed an Amazon link to an Aspen tree poster so that you can see the beautiful trees, although the poster is in the fall..gorgeous, huh?