I bought two bagged 3ft appletrees at home depot about a month ago (I know I shouldn't have bought trees there but they had 2 cultivars I didn't have and I was already there getting something). I planted them in the ground about 3-4 days later and it has since been about 3 weeks. They haven't leafed out yet though, the other apple trees I have around have begun to leaf out and flower in the past week or so but these 2 have zero activity. I peeled the bark back on one of the branches and it is still green and they don't look dried out or crispy, they just don't seem to be interested in leafing out. Are they dead or just slow to leaf because of when they were planted?
Bare root trees have been in refrigerated storage for months, and that makes them think it's deep winter. The trees already in the ground are aclimitized to the local weather. Just be patient. As long as you see green cambium, the tree's alive.
I've been told that the sawdust the mulch the bareroots with is treated with some kind of sprouting inhibitor, so there may be lingering effects of that too. Don't give up, it will happen.
Also, leafing out is variety specific. The Brown Snout is last, again. Hasn't even started to show green. Redfields were leafing out more than 3 weeks ago. Northern Spy and Calville de blanc seem right about in the middle. Does not seem to be related to rootstock, but I will try to remember to watch that next year. I've got Roxbury Russet on 4 different rootstocks so I ought to be able to observe something useful. Mostly what I observed this year was a lot of damage from the 20 deg freeze on April 30.