From our perspective as plants, the concept of an "ideal" environment is not an arbitrary number but the replication of the conditions in which we evolved to thrive. For us Birds of Paradise (Strelitzia reginae and Strelitzia nicolai), our ancestry lies in the warm, coastal forests and riverbanks of South Africa. Here, we enjoy consistent warmth, bright but often filtered sunlight, and moisture-laden air. Therefore, the ideal temperature and humidity you provide should mimic this tropical to subtropical native habitat as closely as possible to encourage robust growth, strong root development, and, most importantly, our magnificent and iconic blooms.
Our metabolic processes, including photosynthesis and nutrient uptake, are highly dependent on ambient warmth. We prefer a consistently warm environment. The ideal temperature range for us is between 65°F and 85°F (18°C - 29°C) during the day. This range provides the perfect amount of thermal energy for our cellular functions without causing undue stress. It is crucial to understand that we are highly sensitive to cold. Temperatures dipping below 50°F (10°C) can cause significant damage to our cell walls and root system. Prolonged exposure to temperatures at or below freezing is often fatal. Equally important is avoiding drastic temperature swings caused by cold drafts from windows, doors, or air conditioning vents, which can shock our systems and lead to leaf curl and browning.
Humidity, the amount of water vapor in the air, is arguably just as important as temperature for our health. In our native environment, the air is rarely dry. We thrive in humidity levels of 60% or higher. This moist air is vital because our large, broad leaves constantly undergo transpiration, releasing water vapor into the atmosphere. In an environment with low humidity (common in heated or air-conditioned homes), the rate of transpiration accelerates dangerously, causing us to lose water faster than our roots can absorb it. This results in the familiar and distressing symptom of leaf tips and edges turning brown, crispy, and splitting. Adequate humidity keeps our stomata (the pores on our leaves) functioning optimally, allowing for efficient gas exchange and preventing excessive water loss.
While we desire consistency, we can tolerate slight seasonal shifts. During the active growing season (spring and summer), the higher end of the temperature and humidity ranges is most beneficial for promoting new leaf growth and flower production. In the dormant period (fall and winter), temperatures can gently drift towards the lower end of our comfort zone, around 60-65°F (15-18°C), but must never become cold. This slight cooldown can actually be beneficial for triggering a bloom cycle in the following season. For indoor caregivers, achieving ideal humidity often requires intervention. Grouping us with other plants creates a beneficial microclimate through collective transpiration. Placing our pot on a pebble tray filled with water (ensuring the pot sits above the waterline) or using a room humidifier are the most effective methods to provide the atmospheric moisture we crave.
