Timing Proper Pruning/Trimming
After autumn the dense leaves that covered your trees has gone and you are left with nothing but scrawny branches. It is a great opportunity to make note of any branches that may need to be removed. It allows you to see what branches need to go so that come next year your lawn is not consumed by overbearing shadows of overgrown branches.
At this point depending on where in the United States you are located, it would be the ideal opportunity to trim and prune your trees. Since you are located in the Midwest if pruning is necessary because branches are dead and the tree or shrub causes a safety hazard, pruning can be performed at any time. However, for example oak trees should only be pruned in the winter months when the trees are dormant to prevent the spread of common fungal diseases.
A good rule of thumb would be to do a light trimming in the spring and fall to aid with the neatness of the shrubs and trees. Heavier pruning is recommended when the tree is dormant, preferably in late fall and winter before active growth begins. Avoid pruning and trimming trees and shrubs should not be performed late in the season to avoid the risk of extreme cold temperatures damaging tender new growth.
Pruning of any kind can encourage new growth. If not sure when your shrubs or trees have been pruned it is better to ask an expert to analyze them and make the proper recommendations. Trimming shrubs and tree limbs can be a great improvement to the look and health of your total landscape overall.