Acorn

The soil decides the tree. Drop one on corrupt grass and you get ebonwood, on snow you get boreal, on sand you get a palm rather than a cactus, and so on down the list. An acorn is a way to move a wood type home, not a way to grow oak specifically. Once placed it is gone: breaking the sapling returns nothing, so plant deliberately.

Smart cursor already knows the spacing rule and will place saplings far enough apart to grow, which is the fastest way to lay out a tree farm without counting tiles by hand. Saplings need time and clear sky, or a dose of fertilizer to skip straight to a full tree. Fertilizer also lets one grow in front of a wall, which a sapling will otherwise refuse to do.

• Trees you plant come out shorter than the ones the world generated. Infused Fertilizer is the only way to get the tall ones back.
• Gemcorns start as acorns, so keep a stack around once you are farming gems.
• They are also ammunition for the Acorn Slingshot, which is exactly as serious as it sounds.