Last year I read an article about using Bonsai trees on a model railway, just for those that do not know, Bonsai trees are not a special type of tree, but a method of cultivation, take any sapling, constrain the roots (and trim occasionally) and keep the top pruned, that is the basics of Bonsai.
Anyway, I have kept Bonsai for a number of years, including a number of native species, so last year I planted a Hawthorn (in a plant pot) in my railway, other than a “haircut” earlier this year no extra treatment including no watering, and it has thrived:

So this year I have prepared a number of trees, sycamore, birch, salix, hawthorn, prunus, and a couple of bought dwarf conifers, and planted them out:

Hopefully soon, I will have a section on plants on the railway, and i will provide more details.