It is for my friends father 
Vegetations are Paint Forge grasses, few types, leaves are from natural leaves cut with RP Toolz cutter. Great tool, for price of 1 or 2 boxes of ready leaves you got infinite amount. I have used also hemps for hydraulic repairs. They can be cut and plant using white glue. Good way to add some variation. They can be painted later with any colour to fade in the rest.
For glueing the leaves I used white glue and CA in some spots. The first layer of leaves was rough, mixed and crushed together in fingers to give the base. Then I have sprayed over Tamiya smoke with some clear red and yellow for contrast ans damp effect from glossy paints. Then overlayer of leaves was glued with CA one by one to fine detail. Here and there I have added some shadow with oil wash of dark colour.
For moss between concrete I’ve used fine sponges, I have tried to do moss with velvet, but it was bad idea. Small sponge of dark colour painted with green oils did the job.
Mushrooms are from putty, painted with oils even without primer. Just 5 minute job.
I have put a lot of oil washes over the base. Some green to simulate mossy ground, some brown, some blacks. Work till effect is satisfactory and stop then