Temperature
- During Tulasī’s growing season, she does best in temperatures ranging from 80 degrees F (27 degrees C) in the day to about 65 degrees F (18 degrees C) during the night. She can withstand temperatures over 100 degrees F (37 degrees C) and even in the low 50s (12 degrees C); but these can cause her stress and will slow her growth.
- Tulasī can overheat and wilt in extremely warm wealther, notwithstanding having an adequate amount of soil water. If this happens:
- a. Don’t water her-this will drench her soil.
- b. Take her out of the sun and into filtered light.
- c. Reduce her temperature by spraying a fine mist of water over her.
- d. When the humidity is very low, increase it around her (see humidity section). This will lessen the amount of water she loses from her leaves.
- e. When the humidity is very high and water cannot evaporate from her, heat doesn’t dissipate very well. Therefore, try to improve the circulation of air around her.
- Tulasī Devī is very sensitive to cold weather. When night temperatures are regularly in the forties, she may have great difficulty surviving.
- To protect her from the cold, bring her indoors.
- If that isn’t possible, and your area isn’t harshly cold, build a simple greenhouse around her:
- a. Use galvanized water pipes as a frame. Place 4 mm clear pastic over them and tape it with duct tape that is weatherproof.
- b. To keep her warm, an electric heater may be placed inside.
- c. The greenhouse must be sufficiently ventilated to avoid build up of heat in the sun.
- If you keep Tulasī Devī inside in a heated area, make certain that she is in a spot that is devoid of cold and hot drafts.
- In a very cold climate, remove her from the window area at night. The coldness from the window could shock her enough to make her give up those leaves and branches that are close to the window.
- Do not place her in the line of direct heat from a heater or cold from an air conditioner.
- Hot drafts could cause her leaves to drop, shrivel up, turn black overnight, or even destroy complete branches or the entire Tulasī plant.
- In homes, heated air is often dry, so make certain that Tulasī Devī is not affected.
- Extreme temperature changes between day and night, or any sudden temperature change creates stress on her. This can cause her to wilt. On such mornings, expose her to the sun gradually, let her warm up slowly, and keep a high level of humidity around her.