Do you have pictures? I couldn't guess what the plant is without a picture, some might be able to. There's a lot of mislabeling going on in nurseries, but mint and oregano like different conditions, so one should suffer if you are treating them both the same.

Thanks- I will post photos tomorrow.
Jo

I have an Italian Oregano w/ lavender flowers, or at least that was how it was labeled! It does look like an Oregano plant though. Greek is tbe one preferred for cooking, which I hadn't realized when I purchased it. I'm not sure on your white-flowered plant.