depends if you mean geraniums or pelargoniums [bedding geraniums]
I don't dead head the hardy perennial geraniums but I do dead head the pelargoniums. They usually keep flowering through the season.
welcome to GoY too.

I do dead head my geraniums as I find they look untidy, they seem to keep flowering longer also.

Welcome to GoY from me also

I do too, and the hardy geraniums have just had a light trim and hopefully will start flowering again soon