San Francisco Real Estate Professional
Though Friends of the Urban Forest only plants tree species that are tolerant of drought, every young tree will need weekly irrigation in order to get established. We recommend watering 15-20 gallons in one watering every week for the first two years, and 15-20 gallons every other week in the third year.
After three years, most trees are established enough to grow on their own and only need supplemental irrigation if they show signs of distress.
Going into the rainy season it is important to still water your tree, even if it rains. A useful rule of thumb is that 1″ of rain is equivalent to 5 gallons of water.
Though trees love getting regular water, it is possible to over water trees. Overwatering can occur when the tree gets more than 20 gallons per week, and can often show the same symptoms of underwatering – drooping, browning, yellowing or dried out leaves, or loss of leaves altogether.
This is most common in thick clay soils with poor drainage. Keep an eye on the soil, and use a trowel to dig about 3 inches down – if it’s still moist, don’t water.