| Yellowing of leaves surfaces, often with brownish burned areas, occurring on leaves that are more exposed to sun, is caused by more sun exposure than the plant is able to tolerate. Some varieties need shade, while all plants that have been protected from direct sun will be tender until hardened off by gradual exposure to sun light. Possible solutions are to give the plant more shade or move it to a more protected site. This often occurs after a plant has been moved to a sunnier location or been pruned. Freeze burn will cause the same thing. Often there is a grayish appearance to burned areas in the leaf, or total browning, depending on the severity of the cold. |
Here is a link that might be useful: Common Problems and Their Solutions.
