High temperatures can slow or stop plant growth altogether, particularly in greenhouses, and cause scorching of leaves and flowers. Foliage may wilt, turn yellow or brown, become dry and crisp and die. Plants placed next to the glass in greenhouses are particularly vulnerable to scorching.

Control

Apply adequate shading to greenhouses and ensure that there is sufficient ventilation to keep temperature down. Damping down the floor of a greenhouse or conservatory with water on hot days will temporarily lower the temperature as well as increase humidity. Move plants away from the glass, especially from any faults that may magnify the sun's rays.