Marigold Flower Temperature. Minimum temperature for growing marigolds is 10C. 06072020 Temperatures of 40 F might not kill healthy marigolds but when the air and ground around the plants hit the freezing mark your marigolds will die.
They tolerate a wide range of temperatures but can get powdery mildew in damp or humid summers. 02072020 Marigolds dont require deadheading but if dying blossoms are regularly removed it will encourage the plant to continue blooming profusely. 06072020 Temperatures of 40 F might not kill healthy marigolds but when the air and ground around the plants hit the freezing mark your marigolds will die.
Be careful not to sprinkle water on the flowers of tall varieties otherwise they become water-logged and soft.
Avoid frost chilling injury. Also what is the lowest temperature petunias can tolerate. Gardeners in all planting zones have to replant them every year. When you water marigolds allow the soil to dry somewhat between waterings then water well and repeat the process.