Frost sensitivity of some trees

We had a late frost on Friday, and I just discovered that some young trees that are totally adapted to our climate here are sensitive to frost. We had red oaks, black locust, and some other nut trees that have burned leaves now. Some of the oaks were just putting out their first leaves as seedlings. On the other hand the apple trees didn't seem to be affected.

Temperate trees which leaf out with frost-tender foliage usually have some lower buds in reserve and are able to leaf out a second time. In fact most trees do this.....it enables them to recover from a defoliation by caterpillars or whatever during the growing season.

We had the same thing happen here in Denver. We have tons of trees that look like they are dead. three or four inch , dried up, new growth. I am hoping they will come out of it.

How long does it take for them to rebound?