Are you by chance feeding with every watering...? If so...discontinue that practice, and follow manufacturers directions. Plain, properly ph'd water between feeding days, but let the pot dry-out a tad between waterings. (don't keep the soil saturated)

I live in the Desert, and almost every day I'll add about a quart and a half of properly ph'd water to my 5 gallon nursery pots. (mature plants) But then, normal room temp in my flower shed is around 95.

If that isn't the problem, you'll need to fill out the troubleshooting form. The link is in my signature. Copy-n-paste it here, and answer all that you can.