Is there any way to tell what kind of hydrangea I have if it has not bloomed? I have two hydrangeas side by side; one is in almost full shade, the other gets a little morning sun--the latter blooms. The one in almost full shade has not bloomed, and I have not pruned it at all for the past two years. If I should move it from full shade, when should I do that?
Most Hydrangeas need some sun in order to produce flowers. The best times of the year to transplant shrubs are spring and fall. Wait until after the hottest summer days have subsided -- September/October. See Hydrangea growing tips: https://ag.umass.edu/home-lawn-garden/fact-sheets/growing-tips-hydrangeas-pruning-for-blooms.
If you want to send us photos of your plants, we can at least try to identify if they are big-leaf, panicle, smooth, or oakleaf hydrangeas. Pruning recommendations vary for each type. Here is our guide to pruning hydrangeas: https://extension.umd.edu/hgic/topics/guide-pruning-hydrangeas.