Natural Propagation

Trees that are already in the world occasionally plant saplings in the area around them. Each sapling matches the species of its parent tree, and the mod works with several vanilla tree species. Over the course of play, forests spread into open land, and grass and snow layers are replaced by the new growth where needed. The process runs while the game is being played, only in loaded chunks, so it adds activity only where a player is present.

The mod suits players who want forests that keep growing across a long game, or who are building packs around reclaimed and overgrown landscapes. To limit crowding, a sapling is not placed where it would sit among nearby logs, and the timing and search radius are configurable. The mod is not a worldgen overhaul and adds no new biomes or structures. Natural Propagation is built to stay lightweight. It needs NeoForge and runs on the server, so players on a setup without it still join the same world.

The server requires the mod, while clients may leave it out. The mod is for NeoForge only, with a single build for 1.21.1 that was published on 2026-05-06 on the alpha channel. It is released under All rights reserved and is not open source.