From a botanical perspective, azaleas (which fall under the genus Rhododendron) are not naturally adapted to life as permanent indoor houseplants. They are temperate climate, woody shrubs that evolved to experience a full annual cycle of seasons outdoors. Their physiology is hardwired for a period of winter dormancy triggered by cooler temperatures and shorter day lengths. Attempting to grow them perpetually in the stable, warm conditions of a typical home goes against their fundamental genetic programming. They are not tropical understory plants like many common houseplants; they are outdoor landscape shrubs that can be temporarily enjoyed indoors.
The single most important factor for an azalea's long-term survival, whether indoors or out, is fulfilling its need for a dormancy period. After the blooming cycle concludes, the plant must be exposed to temperatures between 40-55°F (4-13°C) for several weeks. This cool rest is not optional; it is a vital physiological reset. It allows the plant to conserve energy, initiate new bud formation for the next year's flowers, and simply rest. Without this chilly hiatus, the plant will become weak, fail to rebloom, and slowly decline, succumbing to pests or disease due to stress. An indoor azalea is a temporary guest; it must eventually move to a garage, cool basement, or sheltered outdoor space to complete its life cycle.
When you first bring a florist's azalea indoors or are enjoying its bloom, providing the right environment is crucial for short-term health. They require very bright, indirect light. A south or east-facing window is ideal. Direct hot sun can scorch their leaves and flowers. The root ball must be kept consistently moist but never waterlogged. They are notoriously intolerant of drought; allowing the soil to dry out will cause immediate leaf wilt and drop, and may kill the plant. They also absolutely require high humidity, far above the level found in most heated homes. Placing the pot on a pebble tray filled with water or regularly misting the leaves (not the flowers) is essential to mimic the moist air they crave.
The indoor environment presents several significant stressors for an azalea. The low humidity common in homes causes leaf browning, bud blast (where buds dry up and fall off before opening), and makes the plant highly susceptible to spider mites, which thrive in dry conditions. Tap water, which is often alkaline and contains chemicals like chlorine and fluoride, can be detrimental. Azaleas are acid-loving plants and require acidic soil. Using distilled, rainwater, or filtered water is preferable. Furthermore, the warm, dry air of a home accelerates the plant's metabolism during a time it may be trying to slow down, leading to exhaustion. The combination of dry air, improper watering, and lack of a dormancy period is typically what leads to the plant's demise indoors.
