Traditional sprinkler systems can have bubblers installed next to trees or shrubs which provide a localized and low pressured flow of water directly onto the rootball of a tree.
Traditional Sprinkler System Bubbler
Rainbird Micro Drip Bubbler
To be able to use bubblers as a way of watering, the irrigation system must have the trees isolated on their own zone. When a zone turns on the bubblers shouldn’t turn on at the same time as the rotary sprinklers in the lawn or sprinklers in the flower bed. Ideally, irrigation systems should be designed so that the zones run separately amongst the lawn, flower beds and trees since their watering frequencies and water volume requirements can vary greatly. If the sprinkler system has bubblers on the trees but they are not on their own isolated zone then we would recommend that the bubblers be replaced with caps to discontinue use so the trees do not receive water when that zone runs. In that event, trees should be manually watered by either using an ArborRain Hydration System, Drip Irrigation System, Garden Hose or Tree Gators.
There are several different bubblers to choose from which include: Adjustable Flow Rate, Pressure Compensating (Fixed Flow Rate) and Micro Bubblers (see drip irrigation). The adjustable flow rate bubblers allow for the most manipulation as the flow can be variedin situations when there are different tree sizes on the same zone or slowed down if there is water is running off the rootball or varied when individual tree(s) needs more or less water than their peers. For example, if there is a 95g and a 45g tree on the same zone then each tree would need to have different flow rate.
No matter the type of bubbler used the flow rate needs to be determined. We recommend that customers target a flow rate of .75 gallons per minute or slower. A flow rate of .75 gallons per minute should take approximately 80 seconds to fill up a 1 gallon container. We like to target slower flow rates like this to ensure that there is no run off. Normally when customers start to exceed 1 gallon per minute water tends to run off the rootball and any water that is running off the rootball doesn’t count. If there is any run off, then a slower flow rate should be targeted until the run off is eliminated. Our flow rate calculator can be used to verify that the tree(s) are being watered for the correct number of minutes and that the correct number of gallons are being applied each watering.