This is my tiny little burr oak tree that i planted last fall i think, or maybe late summer. It has put on about 6 inches of growth! If you look closely in the 2nd pic, you can see where the new growth starts. Difference in color. #grownostr #trees #permies #gardening 
Discussion
How deep and how wide is the mulch around it?
I made a square, mulched box for it, approximately 3-4 ft. The greenery around it is some daikon radish seeds i spread in there, to help loosen the soil. These will die off when it gets hot.
Mulch is maybe 3" deep.
The best results I ever had was a diameter 2x the crown diameter and a minimum of 6 - 8 inches.
Of course, I had sun baked, hard-ass clay soil that was like a brick wall. After I mulched new trees as above I saw the best performance I ever saw. One year later, I hardly had to water and the soil under the mulch was dig-able with my hand.
if your brrrr oak tree is cold, then put a coat on it!