Why Do My Fresh Herbs Taste Bitter?

I have never planted herbs before, but went to the nursery and chose 4 for a patio pot. I have chives, lavender, parsley, and rosemary. I pinched them and tasted and they were terribly bitter! So I clipped the old foliage and the new that is growing back is bitter, also. What is wrong? I could never use this in a salad, etc. The worker at the nursery potted them for me, so I don't know what he used. Any ideas? Thanks, as this is my first time asking a question.

Hardiness Zone: 8a

By J.R. from Moultrie, GA