I have a potted white pine a little over 1 foot tall that I intend to plant in the yard.
I live in Illinois, where it should be cold now, but it’s only cool.
Is it better to plant it in the ground now (in the fall), or wait until spring to plant it? If I wait, is there special care a potted tree needs in the winter months?
Contact your state forestry office and/or university agricultural extension office.
Planting now will allow the tree an entire winter to grow new roots and establish itself.
I have planted hundreds of White pines and always did so in the spring. However depending on where you live it might be okay to plant now. If you live somewhere with a mild winter, a short spring and a dry summer it might be preferable to plant now. If you have a cold winter it would probably be preferable to wait.
There should be enough time before the ground freezes for the tree to do a little rooting if you plant now. At any rate, it’s better off in the ground than in a pot.
White pines are tough; yours will probably be OK. Make sure it’s watered adequately before the ground freezes.