Question
We have planted about 200 starts of ponderosa pines on property along the Methow River in eastern Washington state. Soil varies on the property from rocky and sandy to some areas of more fertile river bottom soil.   Water is provided to the base of each tree using a drip line.  We recently had temperatures of 90 degrees plus so we set the timer to water every day for 45 minutes instead of every third day as we had been doing.  Some of the trees are now showing signs of stress, with drooping top needles and the limbs below are beginning to sag.  Are we over watering and can this be reversed if we quit watering for a time?  Help!  We have invested much time and expense into these trees.  I might add that many have been in for two or three years and had excellent growth this spring; up to 18 inches on some.  Also, is it advisable to fertilize young ponderosas?

Answer
Trees do not need water based on temperature but on the lack of rainfall. Trees need about 1 inch of water each week. You can put a pan under the dripline and see what the out put is and from that determine how long to run the dripline. I would water every week with 1 inch of water when it does not rain. Water good now and then start the weekly watering schedule.  The idea is to deep water getting the soil moist down to 8-10 inches. If you lightly watering, the plant grows roots near the surface and during dry weather the plants roots can not reach the moisture. Deep water trains the roots to grow deeper and then they can better survive during dry weather. I would not fertilize if you are getting growht like you say, pines generally do not need much fertilizer.