From my perspective as a Guzmania, the issue you call "root rot" is, fundamentally, a crisis of suffocation. My roots are not just anchors; they are living, breathing organs that require oxygen to function. In our natural epiphytic habitat, we grow perched on tree branches, our roots loosely anchored in a mix of decaying leaves and moss. This environment is airy and well-ventilated. The problem begins when I am planted in a potting medium that behaves like a wet sponge instead of a porous nest. When the medium is too dense or retains water for too long, the air pockets around my roots are flooded. My root cells begin to drown, unable to respire. This initial drowning is the critical first step. Weak, oxygen-starved roots are then extremely vulnerable to invasion.
Once my roots are weakened and damaged from lack of oxygen, they become an easy target for silent, ever-present enemies: soil-borne pathogens like Pythium, Phytophthora, and Fusarium fungi. In a healthy state, my roots can resist these organisms. But when they are suffocated and their cellular walls break down, these pathogens seize the opportunity. They invade the damaged tissue, consuming it and spreading rapidly through my root system. This is the "rot" you observe. The pathogens effectively block my vascular tissues, the crucial pipelines that transport water and nutrients from my roots to my leaves and magnificent flower bract. Therefore, even though the soil may be wet, I am dying of thirst and starvation because my plumbing has been destroyed from within.
Several human actions can create the conditions for this disaster. The most common is excessive kindness—overwatering. My central cup (the tank) should hold water, but my roots should not sit in constantly soggy soil. A pot that is too large is another problem; the excess soil holds more water than my small root system can use, staying wet for far too long. Furthermore, a pot without drainage holes is a death sentence, trapping every drop of water. Finally, using a standard, heavy potting soil instead of a special loose, chunky orchid or bromeliad mix guarantees compaction and poor aeration, setting the stage for the suffocation and rot to begin.
If you catch the problem early, there is hope. You must act with the urgency of a surgeon. First, gently remove me from my pot. You will see the evidence: healthy roots are firm and often have a reddish tinge, while rotted roots are brown, black, mushy, and may smell foul. Using sterilized scissors or pruners, carefully cut away every single rotted root. Be ruthless; any rot left behind will spread. After the surgery, you can dust my remaining healthy roots with a fungicide like sulfur or cinnamon as a protective measure.
Do not return me to the old, contaminated conditions. Choose a new pot that is only slightly larger than my remaining root ball, and ensure it has excellent drainage holes. The most critical step is the potting medium. You must use a fast-draining mix specifically designed for bromeliads or orchids. Ideal ingredients include orchid bark, perlite, coarse sand, and charcoal. This mix mimics my natural epiphytic home, providing stability while ensuring maximum aeration around my roots. When repotting, plant me only as deep as I was before to prevent stem rot. Water me lightly to settle the new medium around my roots, but then, crucially, allow the top few inches to dry out before watering again. Remember to keep my central cup filled with fresh water, as this is how I am designed to drink.
