Questions we frequently get about watering trees are “how much do I need to water”, or even “should I water my trees?” The answers are it depends and yes, respectively. During dry weather, trees benefit from supplemental water just like any other flower or shrub. Too little water can stress trees making them susceptible to disease and insects, and eventually lead to death. Too much water can also lead to stress and the symptoms can appear similar to those of drought. These tips should help hone the amount of water needed.
Tips for Watering Trees
Trees are able to utilize water best when it slowly infiltrates the root zone. This is also a great way to reduce waste, because watering too fast creates runoff. A great way to achieve slow watering is with a soaker hose placed at the dripline (the outermost area of the canopy) of the tree.
Water trees at a rate 3 gallons per diameter inch, measured at breast height, for small trees (less than 8 inches). For larger trees (8+ inches), 5-7 gallons per diameter inch should be adequate, however well drained sandy soils may require more. This can be easily measured with a cheap water meter.
Mulch is a great way to maintain the soil moisture for long periods of time between watering. Remember to keep it away from the trunk and no more than 4 inches deep.
Water content in the soil can be measured with a soil probe (or a screwdriver). The tree still has adequate water if the probe is able to be inserted six inches below the surface of the soil.
Avoid Wetting the Foliage
Avoid wetting the leaves as this can increase the chance of fungal pathogens.