I have or had six pine trees we planted 20+ years ago. I lost one four years ago and I am losing one now. It will not survive the summer. These trees are thirty to 40 feet high. Five years ago one started to look like it was not getting enough water. They are 60 feet from a river and the water table is around 15 feet and less in the winter. The topsoil is about three to four feet deep where the trees are planted and under that is river rock. The trees are located toward the end of the septic tank drain field, about 20 feet away. These trees did great until the five+ years ago. They started to turn brown on the end of the needles. This happened for a couple of years but recovered in the winter. I tested the soil and PH and balanced it all around the house, however it was close anyway. The maples went nuts and started to grow 20 feet a year and the rest of the trees, pines, firs and cedars did real good too. A year later the brown needles came back around mid July. The trees were watered extra and the one tree started it brown needle stuff again next July.
I took a sample of the tree limb to the local nursery, but they said it may be a lack of water, but he was not sure because it looked pretty normal. Trust me it is not a lack of water. There are five trees within eight feet of each other and they are fine. A friend found about something called rust that attacks the roots of the white pine and I guess it stops the tree from drawing water but this tree is between the others and it would seem they would have caught it first and if the first tree that died could have spread the problem to the ones that were closer. They are white pines if that helps. They all put out cones this year except the one that is dying now. The rest of the trees look great except one and the one that is a goner. It will most likely die in the next two or three years like the others. I hate to loose these trees, as my children planted them when they were little. I have looked this problem up on the internet, books, took it to several places and so far nothing.
I have a few fiends who have asked people at the University and they all say it looks OK to them. Several said that pines look like that during the late summer, but my other ones look fine throughout the summer. When I water the lawn they get water too. During the hot parts of the summer I water the trees too. I have two other little pines. I am not sure what they are called because they came from a nursery where the trees are grafted from a pine tree that grows on the coast off the edge of the high cliffs. They are small pine shrubs I guess and they use the root from this tough little pine and a small round pine tree on the top. It takes the shape of a big ball with a short stalk about four feet high. They are both doing great too. Any ideas would be great and if needed I can take pictures. Thanks for the great site. Kind regards Dent
I'm not a tree expert by any means but after reading your post a couple of things came to my mind.
I'm not sure where you are located, I am in the south east, the mountains of North Carolina to be exact. I have about 30 acres here with native white pines. Every year we lose several. The only thing I have heard that is causing it is something called blight.
Another thing that comes to mind is you mention that you are watering them, I wonder if maybe they might be getting too much water. Particularly if they are close to the river. White pines have very deep tap roots and I would think they would not need additional watering. Just a thought