Question
I have several red Japanese maple trees that are very lovely. This spring we had 4 days that the temperature went below 20 F. The leaves were already on the trees and they died and fell off. A small portion of the trees sprouted new leaves. Should I trim them back to the level where the leaves are or should I let them go until next year and see how much of the trees bear leaves?

Answer
Before you decide to trim back the branches you first should check to see if they are dead. Hardwoods after the leaves have been burned by a frost will put on new leaves. Start at the end of the branch and scrape a little of the bark off if the color under then bark is green the branch is still alive at this point of the branch so just leave it be. If the color under the bark is brown the branch is dead at this point on the branch. If the color is brown, continue down the branch scarping at intervals and check under the bark if the color is brown continue down the branch to the trunk. If all the branch is brown (dead) then you can prune this branch. On branches that are  dead at or near the tip and green further down I would leave and see where the new leaves will bud out OR you could prune the dead part of the branch off. In any case I would not cut until you know the branch is dead.