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Drip line and parts calculator for raised beds

One 4 × 8 ft bed with rows 12 inches apart takes 32 feet of 1/4-inch dripline: four rows of 8 feet, with 32 emitters at 12-inch spacing. Enter your beds to count every part.

Example parts list

32feet of 1/4 in dripline
32emitters
16gallons per hour
The bed from above: 4 rows of dripline, 8 emitters in each.8 × 4 ft

Parts to buy

  • 32 ft of 1/4 in dripline in 4 rows (4 per bed), each 8 ft long
  • 32 emitters, 8 in each row
  • 25 ft of 1/2 in main line
  • 4 1/4 in barbed connectors, one where each row joins the main line
  • 4 end closures or plugs, one at the end of each row
  • 1 end closure for the main line
  • 1 elbow for the turn in the main line

Rows sit half a row spacing in from each wall. Buy a few spare connectors and goof plugs for holes punched in the wrong place.

Example: one 4 × 8 ft bed with rows 12 inches apart. Replace it with your beds.

Rows and emitters

Rows run the length of the bed, spaced as your plants need, starting half a row spacing in from each long wall. Makers sell ¼-inch dripline with emitters at fixed spacings; DIG offers 6, 9 and 12 inches. The emitter count is the row length divided by that spacing.

How long one row can be

A run that is too long starves the far end. DIG gives 16, 22 and 28 feet as the longest run for its ¼-inch dripline at 6, 9 and 12 inch spacing, at 25 psi; the calculator warns when a row is longer. Raindrip gives 50 feet for its ¼-inch tubing. Use your own dripline maker’s figure where it differs.

Flow

Total flow is the number of emitters times the flow of each, printed on the dripline. DIG recommends no more than 220 gallons per hour on one run of its ½-inch tubing; split larger gardens between runs or faucets.

The parts

What each part does and the sizes that fit together are on the drip parts pages, including fittings and ½-inch tubing sizes. To check a complete kit against your beds and faucet, use the irrigation fit checker.