Trees slow to break buds
I planted about twenty large trees last fall and most have leafed out this spring and appear to be doing well with three exceptions. I have a large legacy sugar maple, a large scarlet maple and a large nuttal oak that have all yet to break bud; meanwhile everything else in my yard, and all around us for that matter, is green and leafy (we are located in upstate South Carolina - zone 7). These trees were all large balled and burlapped trees (around 15 ft tall, 2" diameter trunks). Scratching the cambium of the tree reveals that they are all still alive though the buds do not seem to show any signs of swelling. Any thoughts as to whether or not they will recover from transplanting or are they gonners? Do transplanted trees typically take longer to break bud? I appreciate any help. Thanks.