I have hydrangea bushes in front of my home which refuse to bloom.

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

I had the same problem! I solved it by adding a good amount compost around the roots out to the dripline EVERY spring. Also fertilizer is critical so I sprinkled general purpose fertilizer (or fertilizer for blooming plants) around the base EVERY spring. Then mulched. Make sure you clip off all dead wood from the branches every spring too, as soon as it buds out so you can see what's alive and what's dead. Mine bloomed very nicely after this treatment!

If they are facing southwest they are probably getting a lot of sun so make sure they get watered regularly.

Perhaps they get too much sun? Also if you know the variety, see if they need a different fertilizer to bloom the color they should be. Blue likes to be more acid than the pink and white.

to much sun for sure. https://www.gardeningknowhow.com/ornamental/shrubs/hydrangea/hydrangea-not-blooming.htm

try feeding it, get some plant food Read to see which one is best for your bushes

you can’t trim them after the first frost and if u have a terribly icy winter it destroys the blooms

let it b for a year and it should bloom