I bet your soil is a bit too hot, possibly the pH is off a bit?
how are you watering? (rhetorical) -- ensure you water fully so no dry spots, ~20% runoff. Don't water again until top 1" dries.
Also, are you fertilizing? i don't see info in diary on it. Don't, and if you have, stop. Stick to a pH'd irrigation of water one until you see a hint of fade at bottom of plant -- smallest, oldest leaves will be cannibalized first and they can be thrown-away anyway.
I think the watering, if not before, willhelp creat a more stable environment for the roots. and water-only should take care of it for a while in soil.