That was my tought too....looks like water burn. Sure you aren't getting those leaves wet when you water and then the sun is frying them? If not....good luck....no clue.

PS you spraying them with bug spray during direct sun? Could be your problem if you are.
Weedhound Reviewed by Weedhound on . Unknown leaf problem - BROWN and crispy (pics) I have 4 plants outdoors, which have just gone into flowering as of a few days to a week ago all with varied problems... My first thought was it must have been from giving too much fertiliser, but soon realised it couldnt be; because all plants are varied in the number of leaves that are 'sick' and I have been giving them all the same recommended doses, and the fact that I havn't given them any fertiliser for about a week and a half and they've only been getting worse recently. Could Rating: 5