Heat, overnute, suffocation and/or diseases of roots, abnormal ph, overwatering, underwatering, too much nitrogen among other things.

Since we have no idea what conditions you are growing it's pretty impossible to say.

Good luck.
Weedhound Reviewed by Weedhound on . lack of phosphorus??? After searching Jorge's Bible, i would guess it could be a problem with nutes!!! Could something else make leafes curl down??? Heat??? Apreciate any help!!! Rating: 5