Why Do Houseplant Leaves Turn Brown?

Watering

• Houseplants must have water on a regular basis to thrive. However, if you are providing your plant with the improper amount of water each day, it can cause the leaves to turn brown. Always check plant requirements for your houseplant to determine how much water is necessary. Check the soil with your finger before adding more water. Dry soil means it is time to water, while wet soil indicates a need to wait before adding additional water. You can reduce the risk of over-watering by placing your houseplant in a pot with drainage holes in the bottom. This allows the excess water to run out of the pot. While over-watering is a common cause of brown plant leaves, under-watering can cause the same result. Plants that develop brown leaf edges usually need more water. If the leaves are wilted, it means the plant is not receiving adequate amounts of water.

Fertilizer

• While fertilizers are made to enhance plant growth, applying excessive amounts can cause plant leaves to turn brown. According to the University of Kentucky, apply fertilizer every one to three months. Houseplants require a fertilizer that is water-soluble and nitrogen rich. Refer to the label on the fertilizer for application schedules that best suit the needs of your particular species of plant.

Insect Infestations

• Insect infestations can cause your houseplant leaves to turn brown. Spider mites, aphids and mealybugs are common pests of houseplants. Most of these pests are very small, but they can cause a great deal of damage, including reduced vigor, leaf browning or scorching and wilting of leaves. Heavy insect infestations can cause houseplants to lose their leaves prematurely, as well. Light infestations of these pests can be removed by spraying your plant with a forceful stream of water, which helps knock insects from plant leaves. Repeat this process three times each week for best results. Heavy infestations may require horticultural oil products to reduce insects. These products work best when applied thoroughly, especially to the undersides of plant leaves where insects congregate.

Low Humidity

• Indoor plants require a certain amount of humidity to thrive and look healthy. If your houseplants are turning brown, you may need to increase the humidity inside your home. Placing houseplants on a wet tray of rocks or running a humidifier indoors may help increase humidity levels. Move your plants to a more humid area of your home, such as the bathroom, to increase humidity and decrease leaf browning. Be careful where you place your houseplants. Placing your plants near an air vent may cause it to brown and dry out when the warm air from the heater blows on it.