How to get Platinum tree to Elmcreek?

[Kiptanoi]

Hello. How do I do to make it possible for me to buy platinum tree like Small/Medium/large Lodgepole pine in my construction/landscaping menu on the map Elmcreek?

I can see and buy all equipment's from the shop that is in platinum, but I can not plant platinum tree on Elmcreek, or buy those tree from construction / landscaping menu.

What files to edit?

[Noraf]

Short answer? You can't