Drafty Air
If your Sensitive Plant’s leaves are always closed then this could be a good indication that they are experiencing a draft or too much heat. A disturbance to the leaves such as touch, airflow, or heat can cause the moisture in the leaflets to flow out. This loss of pressure is what causes the leaves to close up. Try moving the plant away from any open windows, air vents, or drafty hallways.
Lack of Humidity
The Sensitive Plant loves humid conditions and thrives with regular misting and lots of moisture. Moisture on its leaves is what keeps the leaves upright, so be sure to mist often or add a humidifier nearby.
Not Enough Sunlight
If your Sensitive plant is not getting enough sunlight then its leaves might not open properly. If your plant is often closed-up and looking a bit sad, try moving it to a sunnier location. This should help open the leaves back up. It will be very happy near a south or west window.
Time of Day
Sensitive Plants naturally close their leaves at night, so don’t worry fret if you notice this as you are going to sleep. They should open again in the morning when the sun begins to shine.