I collected a black pine from a residential landscape in mid-spring this year. I kept it in mostly shade and sheltered from wind for about 3 weeks. The tree never showed the slightest signs of stress.

Now, about 2 months later, it is not looking so good. It only started showing browning of older needles and the yellowing of newer growth. I had moved the tree to a position of slightly more sun a month or so ago but it is still very sheltered from wind. The other factor is that as I collected the pine, I mixed in pearlite with the native soil. I didn't mix enough I feel, because the soil is poorly draining. It is slow to saturate and doesn't dry out.

Should I try to repot now at this late date and put it back in full shade? We are having a mild summer to this point.

Or is it that the tree is only now showing the shock of transplant 2 months later?