I've had emails from several people asking how I paint trees.
Yesterday I was painting down the road , in the beech forest with a backdrop of the mountain range. Now, although I know that each of those beech trees has thousands of leaves, I couldn't see each leaf when I was painting. I just wanted to show the colour, tone and shape of the trees, with little detail.To do this I let my colours blend on the damp paper-I added darker, thicker paint to the right hand (shady) sides of the trees. Each tree melts into the one beside it. While the paint was damp, I scratched out a few trunks and branches with the end of my brush (or a stick). In places I dropped in some more dark paint behind light areas (which were dry by then) to really make those light treetops pop out. Sometimes I might splatter a bit of paint on to give the idea of foliage on closeup trees (like the one on the left). and that's it...
Remember that the more water you use, the lighter the final colour.
I prefer to let my pigments mix on the paper, this gives areas of lovely broken colour , as you can see in the chart. If you mix on the palette the result will be flat colour.
I suggest that you make yourself a colour chart like the one above of the the paints that you have- try making greens with all the combinations you can of yellow and blue, then try adding a wee bit of red and see what happens. If you have tube colours of premixed greens like sap green I suggest you add a little red to those rather than use them straight. Most trees have lots of different colours in them , not just green- go outside and take a look....
and if you have any questions please ask, I'm happy to help out.