After much thinking, testing, experimenting and faffing (and not necessarily in that order) I have finally finished adding a tree and bushes, which means that the piece really is now finished (with thanks to all who have aided me over this final hurdle
).
In short, a mature tree just didn’t look like the sneaky interloper that I wanted it to be, so I settled on a look akin to a younger, colonising species (Downey Birch was my guide).
I salvaged the foliage from the mature tree, which became the bushes. This foliage had been made by dry brushing clumps of rubberised horse hair with VMC Military Green, then painting on a very dilute PVA to which had been added some drops of VMA Mud, then sprinkling a mix of equal volumes of Woodland Scenics Coarse Tuft Yellow Grass T61, with Woodland Scenics Coarse Tuft Light Green T63, and Javis Scatter Heath Green No17.
I made the tree by painting a suitable twig with VMC Military Green, then dry brushing with VMC Green Brown, Deck Tan and then finally a bit of Off White. To bulk out the stubs of branches, I used UHU to stick on a few small ‘blobs’ of WS Clump Foliage Light Green FC682. UHU was also used to add rubberised horse hair, into which I worked some VMC German Cammo Brown. PVA was mixed with VMC Olive Green and a little water and ‘painted’ in dots, blobs and smears onto horse hair, onto which I sprinkled Javis Scatter Heath Green No17. When dry, I lightly dry brushed the outer leaves with VMC Olive Green.
I also added bushes growing out of the block work:
And with a Perry WotR for scale (it is a big piece):