I have 4 hydrangea plants in my yard & can’t get any of them to bloo

https://www.gardeningknowhow.com/ornamental/shrubs/hydrangea/hydrangea-not-blooming.htm

I assume you forgot to type the word “bloom”. If that’s your question, you need to determine what type of hydrangeas you have. Some hydrangeas produce next year’s bloom on this year’s woody branches (referred to as “old wood), therefore, if you are cutting back your hydrangea this Fall or Spring of next year, you are cutting off the blooms.

Other hydrangeas produce blooms on “new wood” (next year’s growth), therefore, it’s fine to cut back any overgrown branches this Fall. Libraries have good information and, of course, computers are great sources. Google “photographs of hydrangea species” or something similar and see if you can find the types of hydrangea you have in your garden.