On the market you can find lots of solutions for miniature trees. If you like to build a big forest, I suggest to use ready trees. If you want to have a small group of trees you can build them using a real plant, growing on lakes, called erica (see for example Noch): this plant is very similar to small trees. You only have to trim a little branch according your scale then spred it with the powders used for the meadows. We can fix the powders using hairspray: it's an easy and chep way and last forever.

OK, we have finished! Now we must find a good place to plant out tree!