Mints like their soil constantly moist, but not soggy. In a small pot, that soil is going to dry out quickly, especially if exposed to sun and/or wind. (Potted plants are high maintenance.) Put it into a larger pot - it will fill up the pot quite quickly, as the roots of mints are very aggressive growers. But at least for now, more soil=more retained moisture. Come winter, you'll need to water it less, as your plant will probably become dormant then. Meantime, keep up the water, and make sure excess can drain away quickly.

I agree with Daisy', you need a bigger pot. You might also try using this new type of potting soil with water-holding crystals already in the soil; that will help.

Mine too.
It's constantly dry.

Well, it sounds like I'll have to repot it when I get access to a pot and soil. Apartments are terribly condusive to repotting often.

Thanks for your advice! I guess underpotted peppermint in well draining soil could be the salve of the cronic overwaterer.

(sorry, mom, I guess you'll just have to water it more often until you repot too!!)