Ground and slope

Plant on #

natural ground default default

Grass, dirt, sand, snow, mud, moss and terracotta. Never stone, planks or a roof. Blocks from mods count when their mod tagged them as dirt or sand.

what the stroke starts on

The block you start a stroke on is the ground for that stroke. Start on a terracotta floor and only the terracotta gets trees.

blocks you picked

Only the blocks in the list. Add them with Add pointed at or Add in hand, or with G in paint mode. Any block, modded ones too.

anything solid

Any solid block, roofs and floors included.

Slope and the foot of the trunk #

Slope limit default 3

How many blocks the ground may rise or fall under one trunk. Steps of one block are followed by the roots. Steeper than this and the spot is skipped.

Replaces default air, plants

Air and plants: the tree grows around anything solid in its way. Everything: it overwrites it.

A tree stands at the most common ground height under its trunk. The foot of the trunk follows one-block steps: it reaches down into a dip and drops what would be buried. Roots dig through soil and stone, and through the ground you picked.

Spots that are left alone #

Water, spots under the crown of a tree that was already there, and spots steeper than the slope limit. The HUD counts them; see Troubleshooting.