From my perspective, a sudden change in my surroundings is a major shock to my system. If you recently brought me home from a nursery or moved me to a new location, I am likely experiencing environmental stress. My leaves are sensitive to shifts in light intensity, temperature, and airflow. A move from a bright, humid greenhouse to a drier, dimmer home environment can cause me to jettish my leaves in protest. I interpret this sudden change as a threat, and my survival response is to drop what I perceive as unnecessary weight (my leaves) to conserve energy and water until I can acclimatize to my new conditions.
My water needs are specific, and getting them wrong is a primary reason for my sudden leaf drop. If my soil is constantly wet and my roots are sitting in water, they begin to suffocate and rot. Without healthy roots, I cannot absorb water or nutrients, and my leaves will wilt, turn yellow, and drop suddenly as I essentially drown. Conversely, if you forget to water me and my soil becomes completely desiccated, I will go into survival mode. To prevent total system failure from dehydration, I will sacrifice my leaves, which lose water through transpiration, to protect my core stems and root system.
As a sun-worshipping plant, I am highly sensitive to cold. A sudden cold draft from an open window, an air conditioning vent blowing on me, or a drop in nighttime temperatures can be very distressing. When I am chilled, my cellular processes slow down, and water movement within my tissues is disrupted. This can cause my leaves to turn yellow or develop brown spots before dropping off abruptly. I thrive in consistent, warm temperatures, and any sudden cold snap is a signal for me to conserve energy by shedding my foliage.
To produce my vibrant bracts and lush green leaves, I require specific nutrients, particularly phosphorus and potassium. A sudden leaf drop can indicate a severe deficiency; I am simply unable to sustain my foliage without proper nourishment. On the other hand, an overzealous application of fertilizer can have a similarly dramatic effect. A chemical overdose from too much fertilizer can burn my tender root system, causing a rapid and severe reaction where my leaves wilt, burn, and fall off as my roots are damaged and unable to function.
While often more gradual, a severe infestation can cause a sudden deterioration. Tiny pests like spider mites, aphids, or scale insects may be sucking the vital sap from the undersides of my leaves and stems. This theft of my nutrients and moisture weakens me significantly. As a defense mechanism, I might shed the compromised leaves to try and rid myself of the pests and redirect my energy to producing new, healthy growth. Similarly, a fungal or bacterial disease attacking my roots or foliage will cause me to shed the diseased parts to try and stop the spread.
