Over-watering plants can cause a plant’s leaves to turn black. To prevent this, don’t let your plants sit in too much water and make sure that the pot it’s in has a hole at the bottom so any excess water can escape.
If you see white spots building up on the surface of your plant’s soil, it’s generally a sign of salt build-up. Salts can come from the water you use to hydrate your plant, the potting mixtures, and fertilizers. Flush watering a plant regularly will leach out any excess salts and minerals.
Temperature and Humidity
Most house plants are native to tropical areas. They prefer warm, humid conditions. To keep your plants comfortable try keeping them in areas that are between 60 and 75 degrees fahrenheit. Anything below 55 degrees will not be plant friendly. Also make sure that your green space is properly ventilated and relatively humid.