Pinus strobus or White Pine which is the common name of a very popular Midwestern Conifer Tree. We have several of them on both golf courses. This time of year I receive a lot questions about the White Pines. Many people think that they are dying or have a disease, when in fact they are going through a very natural thing for them.
Each year the White Pine puts on new growth, which means new needles. So it looses last years needles and they fall off. Right now last year's needles are very yellow and are falling all around the bases of the trees.
Here is a close up of a typical branch on a White Pine, you can see this year's growth and last year's old needles.
So please remember they are not dying, nor do they have disease, it is just Mother Nature doing her thing.