Cactus Farm (Water Collection) in Minecraft

One cactus automatically breaks against an iron bar. A covered water tray carries surviving drops to three hoppers and an accessible chest.

An elevated cactus grows into the empty cell beside an iron bar, causing the new block to break. The three-wide tray below carries drops south. Some drops hit the cactus or remain on its platform, so collection is imperfect. The adjacent bar also prevents cactus flowers, which require all four horizontal sides to be empty in Java 1.21.5 and Bedrock 1.21.70. This original compact layout is based on documented mechanics and has not been tested in game.

Materials

• 32× Stone bricks
• 3× Hopper
• 1× Chest
• 135× Glass
• 15× Water
• 1× Sand
• 1× Cactus
• 1× Iron bars
• 3× Water bucket

Build steps

1. Build the floor and storage: Coordinates are zero-based (x, y, z), with north at z=0. Build the 5x7 stone-brick floor at y=0. At z=5 replace x=1 with an east-facing hopper, x=2 with a south-facing hopper and x=3 with a west-facing hopper. Place the south-facing chest at (2, 0, 6); the middle hopper points directly into it.
2. Place the suspended planting platform: Before finishing the floor, borrow a few stone bricks from it as a temporary pillar to place the permanent support at (2, 2, 3). Remove the pillar and return its blocks to the floor. Put sand at (2, 3, 3) on that support. The whole y=1 tray must remain clear.
3. Build the enclosure and growth breaker: Build the outer glass ring at x=0, x=4, z=0 and z=6 from y=1 through y=5. Place one iron bar at (3, 5, 3), attached to the east glass wall. Keep (2, 5, 3) empty for new cactus growth. Leave the four sides of the planted cactus at y=4 empty.
4. Fill the water tray: Place water sources at (1, 1, 1), (2, 1, 1) and (3, 1, 1). They flow south through z=2 to z=5, directly above the hopper row. Glass at z=6 contains the stream; do not place a source above the terminal hoppers.
5. Plant and close the roof: Plant the cactus at (2, 4, 3), then cover all 5x7 cells of y=6 with glass. The growth cell at (2, 5, 3) remains air under the roof. Open the chest from outside the south wall; the glass above it permits opening.
6. Check collection and wait nearby: Drop a spare item into each water lane and confirm it reaches the chest. Stay nearby in a non-freezing biome for random ticks. Growth is slow; newly grown cactus breaks automatically, but items touching the cactus are destroyed. Empty storage before it fills.