You can plant fruit trees anytime: 1. the ground is not frozen solid 2. once the tree has gone into dormancy for the winter 3. just as the buds begin to swell 4. any time as long as you account for number 1 in this list and you
water it in well so the soil gets into close contact with the
roots and you add a root stimulant.
The best time is during dormancy the second best time is at bud swell.
The rest of the year you need to be very thorough with your planting technique and give a root stimulant at the watering in of the tree.
I have planted fruit trees in August (our hottest month) and they have done quite well.
If the trees are already in full leaf and have fruits set, you can still plant but transport will require a cover for the tree to prevent leaf burn and you need to simply remove all fruit at planting, it will drop anyway so save the tree that
energy cost.
Redhawk