Each year jonahs dad puts out mum plants on each side of his front steps. An early frost hit prior to the plants entering a state of dormancy, and the mum plants died. What might explain why the plant died?

The plant died due to frost damage and desiccation

Explanation:

Plants may remain alive in an unfavorable condition for long periods without growing any further, but still have the power to grow under favourable conditions. Such plants are said to be in a state of DORMANCY. This is a gradual process that is made up of series of physical and physiological changes in the plant.

During unfavorable condition, such as in winter periods, scales form over buds to protect them from desiccating or drying out, and from the freezing temperatures. The occurance of these changes in plants are time bound. Therefore if there is change in the weather forecast leading to an EARLIER frost hit prior to the plant entering a state of dormancy, frost damage and desiccation may cause the death of the plant. Frost damage and desiccation occurs when there is lost of moisture from plants without it being able to replenish its water supply through its roots due to the dry air and winds.

As the plant wasn't able to enter the state of dormancy, it lost the opportunity to photosynthesize, grow and store more energy before settling in for the unfavorable season.