Measuring Drip or Bubbler Output

Drip emitters are typically used around trees and shrubs and are sized in gallons or liters per hour.

If you have more than one emitter on a plant (and you often should), total the output of the emitters on each plant. For example, if your tree has three 2-gallon per hour emitters, the output will be 3 emitters x 2 gallons = 6 gallons per hour.

If you don’t know the output of your drip emitters, you can remove an emitter and take it to an irrigation supply or home and garden store, or you can estimate emitter output with the diagram at the right.

Bubblers typically apply 1/2 to 2 gallons per minute. Some allow you to adjust the flow and some do not. The flow rate is often stamped on the top of the bubbler.

Now you’re ready to calculate the total emitter output for your plants. This output will help determine run times for each watering line or valve. However, it is not necessary to list every plant in your landscape. You can group them by type and size, such as 15-foot trees, 6-foot shrubs, or 3-foot groundcovers (sizes refer to the diameter of the plant canopy).