> ## Documentation Index
> Fetch the complete documentation index at: https://items.lodemc.net/llms.txt
> Use this file to discover all available pages before exploring further.

# Trees that generate in new chunks

> Let trees grow by themselves in new chunks: choose the biomes, how many per chunk, the ground they stand on, and the dimensions and worlds they appear in.

A [tree](https://items.lodemc.net/flora/trees.md) only grows by itself in new chunks if it has a `generate:` section. Without one, it only grows from its sapling. Procedural trees and trees from schematics both work, made of your blocks or vanilla ones.

```yaml items/flora/willow/willow.yml theme={null}
willow:
  type: flora
  tree:
    log: willow_log
    leaves: willow_leaves
    canopy: weeping
    generate:
      biomes: [swamp, mangrove_swamp, "#minecraft:is_river"]
      per-chunk: 0.5              # a tree in about every other chunk
      on: [grass_block, mud]
```

## Options

**generate** `section or list`

| Key | Default | Does |
| - | - | - |
| `biomes` | required | Biome ids or `#tags` it grows in, such as `[forest, "#minecraft:is_taiga"]`. |
| `per-chunk` | required | How many trees each chunk tries to grow, up to 64. Fractions are chances: `0.25` is about one tree every 4 chunks, `2.5` is 2 per chunk plus a third half the time. |
| `on` | `#minecraft:supports_vegetation` | The blocks or `#tags` it may stand on. |
| `dimension` | `overworld` | `overworld`, `nether` or `end`. |
| `worlds` | every world | Only these worlds, by name. |

Give a list of sections to generate the same tree in different ways, for example often in one biome and rarely in another.

Each tree is placed on the surface, on top of the ground (leaves don't count as ground), never in water, and only where it has room as described in [How a tree grows](https://items.lodemc.net/flora/trees.md#how-a-tree-grows).

> [!WARNING]
>
> Only **new chunks** get trees. Chunks that were already generated are left as they are. Changes to `generate:` apply on `/lodeitems reload`, to chunks generated after that.

For ores in new chunks, see [World generation](https://items.lodemc.net/blocks/world-generation.md).


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