Cut off the bottom a 5-gallon-or-larger bucket. Remove the bottom with a hacksaw or jigsaw.
Measure the PVC pipe and cut it so it is 6 inches taller than the bucket. Drill one-quarter inch holes up each side of the pipe creating four rows of holes, stopping 6 inches from the pipe’s top. Space the holes 1 to 2 inches apart up each row.
Set the bucket in the garden. Choose a location with full sunlight.
Stand the pipe upright in the bucket, placing it near the bucket’s inside edge. Place it, so that the portion of the pipe without holes protrudes above the bucket’s top.
Fill the bucket with a 6-inch layer of soil. Place extra soil around the pipe if necessary, so that it remains upright.
Plant the potato seed pieces on top of the soil, arranging them so the growing eyes face up. Plant three to four potato pieces per bucket.
Cover the potatoes with soil until they are buried to a 3-inch depth. Water the soil until it's moistened throughout.
Add more soil to the bucket as the potato plants grow, so that only the topmost leaves on the stems remain above the soil. Continue adding soil until the bucket is filled.
Water the bucket every one to two days, or when the soil begins drying. Once the bucket is filled, irrigate it by pouring water into the pipe, so that the water leeches down to the soil in the bucket’s bottom.