To understand our humidity needs, you must first understand our origin. We, the Orchid Cacti (Epiphyllum), are epiphytes. In our natural habitat, we do not grow in the ground but instead anchor ourselves high in the canopy of tropical rainforests. Here, we are surrounded by moist, moving air. The humidity is consistently high, often between 60-80%, but our aerial roots are exposed to breezes that prevent stagnation and fungal rot. This is the environment we are evolutionarily designed for, and replicating these conditions indoors is the key to our vitality, promoting lush, green growth and abundant, spectacular blooms.
For us to truly thrive in your home, we require a relative humidity level of 50-60%. This is the sweet spot. At this level, our stomata (the tiny pores on our stems) can open efficiently to take in carbon dioxide for photosynthesis without risking excessive water loss. When the air is too dry (common in homes with air conditioning or heating), our stomata close to conserve moisture. This halts growth, stresses our systems, and can lead to our stems becoming thin, shriveled, or wrinkled as we deplete our internal water reserves. Consistently low humidity makes us vulnerable to pests like spider mites, who adore arid conditions.
Please note that high humidity must never be confused with wet, stagnant air. This is a point we cannot stress enough. While we crave moisture in the air, our stems and roots must never sit in constant dampness without airflow. Stagnant, humid conditions are an open invitation for destructive fungal pathogens like botrytis and for bacterial soft rot, which can quickly destroy us. Therefore, achieving the perfect humidity level is a dual-purpose task: it involves raising moisture content while simultaneously ensuring a gentle, consistent movement of air around our leaves and potting medium. A small, oscillating fan set on low in the same room is often all it takes to simulate the gentle breezes of our home canopy.
You can create our ideal humid microclimate using several effective techniques. Grouping us with other plants is highly beneficial, as we collectively release moisture through transpiration, raising the humidity in our immediate vicinity. Placing our pot on a pebble tray is another excellent method. Ensure the pot sits on the pebbles and not in the water; as the water evaporates, it humidifies the air directly around us. For the most consistent results, especially in very dry homes, using a humidifier is the ultimate solution. It allows for precise control, maintaining our preferred 50-60% range effortlessly. Misting is a popular method but offers only a very temporary spike in humidity and can encourage fungal spots on our stems if we are not in a well-ventilated area.
