To make an automatic cactus farm with no redstone first dig an 8-block line. Then make 2 more separated by 1 block. Make the blocks in between sand. Place cactus every other block. Put a block in the air next to the cactus. Then put water in each 8-block line at the begining. Make a ditch for the cactus to be collected. It makes it really easy to collect cactus. Thank you for reading. Please suscribe and diamond.