What sort of potting medium are you using?

Lady Bug natural brand vortex potting mix

Well, the funny thing is that in the past I used this same potting mix for the peppermint plants that did very well (along with other plants that had no problems), but yes, this spearmint and about 5 other potted plants are using the Lady Bug mix and are having the same problems.

Did you dump the used mix and use fresh for this year? Is there anything unusual in terms of the environmental conditions this year? Perhaps an excess string of rainy, shady days, for example?

New potting mix is fresh (I never resuse soil unless I sterilize it). Yes! My first guess was this year's unusal weather: late May and June's total rainfall was more than we get in total annually, and beginning in July it has been nothing but dry and hot without any rain at all (everyday reaching 100 degrees fahrenheit or more).

Thank you all for the responses

Is anyone else in the 8b zone having the same trouble?

My super healthy sweet mint started looking really scraggly beginning of July, flowered, appeared to die, and now it is growing new leaves from the base and from some of the dead looking stems. Yours is what mine looked like before it flowered.

Also I don't know how different varieties of mint are, but mine could not get enough water being in a pot.. a I literally soaked it into sloppy wet soil every day/every other & it was THRIVING.

That sounds exactly like what happened to mine! But it never flowered, although maybe it was trying to? No idea, but thank you. And now that it's just a tiny bit cooler, it seems to be doing much better. (Also took your advise to water it more)

I have wateredffrequently and it seems to have prompted fungus and rot...Not root bound because i repotted only last year into a container twice size of root mass

When I put it in the sun, it dried up and started to dry out within days...as i was also trying not to overwater

Just can't seem to find right conditions