Automatic Sugar Cane Farm — 3D Build Guide

How to build the sugar cane farm, step by step

1. Hoppers and a chest — Sink a row of 8 hoppers one block into the ground, each pointing east into the next, with a chest at the end. Everything the farm cuts ends up here.
2. Mud on the hoppers — Put a block of mud on every hopper. Mud is two pixels lower than a full block, so a stalk that falls on it lies inside the hopper's pick-up area. On dirt or sand the hopper would not reach it.
3. Water next to the mud — Sugar cane grows only beside water. Dig a one-block channel along the mud and fill it with still water.
4. Glass walls — Raise glass four blocks high over the water and at both ends of the row. The wall keeps cut stalks on the mud and out of the water.
5. Plant the row — Plant sugar cane on every block of mud.
6. Pistons on the second block — Behind the row, at the height of the second stalk block, place a piston facing the plants on a block of cobblestone. It breaks the second block; the bottom one stays and grows again.
7. Observers above the pistons — Put an observer on every piston, its face towards the plants. When a stalk grows into the third block, the observer sees it and sends a pulse out of its back. Cover the observers with glass.
8. Redstone line — Behind the pistons lay a row of cobblestone and a line of redstone dust on it, right behind the observers. The pulse powers the block under the dust, and that block powers the piston next to it — any observer fires the whole row.
9. The farm at work — The farm runs on its own while you are within simulation distance. One plant gives at most about 3.3 sugar cane an hour; in a row with one shared line it is about 2.5, because a plant cut early loses its growth. A row of 8 makes about 20 an hour.

Sugar cane farm — questions

How fast does sugar cane grow in Minecraft?

A sugar cane plant adds one block about every 18 minutes: it needs 16 random ticks per block, and a block gets a random tick about every 68 seconds. One plant therefore gives at most about 3.3 sugar cane an hour, and it never grows taller than 3 blocks.

Why does this farm give about 20 sugar cane an hour, not more?

All 8 pistons share one redstone line, so when any plant reaches its third block the whole row is cut. Sugar cane grows by age, and a plant cut early loses the age its next block had built up. In a test on a vanilla 26.3 server the row collected 73% of the single-plant maximum — about 2.5 an hour per plant, about 20 from the row.

Why is the farm built on mud and not on dirt or sand?

Mud is two pixels lower than a full block. A stalk that falls onto it lies inside the pick-up area of the hopper underneath, so every cut item ends up in the chest. On dirt or sand the hopper would not reach the dropped stalks.

Why do I need a line of redstone dust behind the observers?

An observer sends its pulse only out of its back. Dust behind it powers the block it lies on, and that block powers the piston next to it. A plain block behind the observer does not work: tested in the game, the piston never fired. The shared dust line also lets any observer fire the whole row.

Does the farm work when I am far away?

Plants grow only in chunks that get random ticks, so stay within the simulation distance of the farm (Video Settings in singleplayer; on a server the owner sets it).