WATER ONLY THE PRIMARY NEW ROOT BALL. SATURATE THIS AREA THOROUGHLY FOR ABOUT 10 MINUTES (or, to overflow of mulch ring). It is helpful to calibrate your hose and time how long it takes to fill a 5 gallon bucket. A good rule of thumb is that a tree needs 10 gallons of water per inch of caliper per week during growing season.
DO NOT COUNT ON RAINFALL. THE ROOTBALL OF THE TREE NEEDS DIRECT WATERING AND RAINFALL IS TYPICALLY NOT ENOUGH (UNLESS IT RAINS MOST OF THE DAY).
March through May (from dormant season to spring growth flush of buds and leaves) – at least twice weekly, possibly a third time based on how hot the weather and rainfall.
SUMMER (June through about September) – MAINTAIN 3 TIMES A WEEK. WATCH FOLIAGE TO MAKE SURE IT IS NOT “FLAGGING / OR DROPPING LEAVES”. Some drooping leaves can be normal in the middle of a hot summer day but if a tree has drooping leaves at night or in the morning, watering must be increased. If so, increase length of each watering by 5 to10 minutes more (double) but remember, too much water can be just as bad as not enough.
Fall (October to December) – reduce watering back to once a week / monitor rainfall. Once leaves drop – stop watering or drop back to once every two weeks for about 15 minute duration.
CONSIDER PURCHASING “SOIL MOISTURE METER” (Google this title to see various options and vendors). These provide immediate results. Suggest one that has at least a 12” probe for deeper reach.
Call your arborist with any questions!