Garden Lake Park 6" x 6"

On Saturday I joined 3 others in the Eugene Plein Air group to paint at Garden Lake Park in Creswell.  I had never been there before.  It seems like a promising location to try again.  It was 39*, the coldest weather I've ever painted in.  I managed to stay warm and hope to meet them again on the 30th.
I tried Alizarin for toning the canvas and am happy with that.  I also like how the blue looks shading the red bushes in the foreground.  It was the color I had mixed up for the trees.  I just kind of accidentally used it.  Maybe using a complement can be a shading technique?  Landscapes are difficult for me, but I really want to figure it out.