The saplings, I don't think so, because they're actual trees once placed in the world and have their own internal function in game that prohibits them from being a blueprint. And since I can't blueprint a forest in vanilla, I think I'd have to change the tree code instead of using in-game saplings, which would not only be uber cumbersome but could cause a lot of havoc with other things in game.
You should be able to blueprint tree farms though. So if that isn't working, please let me know.
