Aloe vera plants, known for their resilience, can develop brown leaves. This discoloration often signals an underlying issue with the plant’s environment or care, such as improper watering, extreme temperatures, or light exposure. Identifying the cause is crucial for restoring your aloe’s health.
Common Reasons Your Aloe Plant Is Turning Brown
Excessive sunlight can cause aloe leaves to turn brown or reddish-brown, a condition known as sunburn. Damage typically appears on leaves most directly exposed to light, which usually remain firm. Moving an aloe suddenly from shade to intense sun can cause scorching, leading to yellow or brown areas that dry out.
Excessive watering frequently causes browning and often leads to root rot. Aloe plants store water in their fleshy leaves and prefer arid conditions, making them susceptible to rot in constantly wet soil. Overwatered leaves may turn yellow or brown, becoming soft, mushy, and sometimes translucent, with browning often starting at the base.
Underwatering can also cause browning, though aloe is drought-tolerant. When deprived of moisture, the plant draws water from its leaves, causing them to shrivel, wrinkle, and become dry and crispy, particularly at the tips. This browning typically appears at the leaf ends first, indicating dehydration.
Temperature extremes stress aloe plants, leading to browning. Cold damage, below 50°F (10°C), causes leaves to turn dark brown or black, becoming soft, mushy, or glassy. Conversely, prolonged exposure to temperatures above 80°F (27°C) can cause heat stress, leading to leaf curling, wrinkling, and drying tips as the plant struggles to conserve moisture.
Nutrient issues can also cause browning. Both severe deficiencies and excessive fertilization contribute to leaf discoloration. Too much fertilizer can burn the plant’s roots, leading to browning symptoms similar to other stresses.
How to Diagnose the Specific Cause
To diagnose browning, begin by examining the soil. Insert your finger about two inches deep into the potting mix. If it feels wet or soggy, overwatering is likely, particularly if the pot lacks adequate drainage. Conversely, if the soil is completely dry and the pot feels unusually light, it suggests underwatering.
Inspect the texture and location of browning on the leaves. Mushy, soft, or translucent brown areas, especially at the base, often indicate overwatering and potential root rot. Crispy, dry browning concentrated at leaf tips suggests underwatering.
Evaluate the plant’s light exposure. Browning or bleached spots on leaves facing direct light suggest sunburn. If the plant is in a dim location and still browning, low light might weaken it, making it susceptible to other stressors. Consider recent temperature fluctuations; dark, mushy browning often occurs after cold exposure, while wilting and drying result from excessive heat.
Solutions for Browning Aloe Plants
If sunburn is the issue, relocate the plant to a spot with bright, indirect sunlight, such as a south or west-facing window filtered by a sheer curtain. For outdoor plants, gradually acclimate them to brighter conditions over several days to prevent shock.
For overwatered plants with soft, mushy browning, stop watering and allow the soil to dry completely. If root rot is suspected, remove the plant from its pot, shake off old soil, and trim any dark, mushy roots. Repot into fresh, well-draining succulent or cactus mix in a pot with drainage holes.
If browning is due to underwatering, give the plant a deep, thorough watering until water drains from the bottom. Allow the top few inches of soil to dry out before the next watering, but avoid prolonged dryness. Severely dried leaves may not revert to green, but new growth should be healthy with consistent moisture.
For temperature-related browning, move the aloe to an environment consistently between 55°F and 80°F (13°C to 27°C). Protect plants from cold drafts and intense afternoon sun or extreme heat. Trim severely cold-damaged leaves to allow the plant to focus energy on new growth.
Preventing Future Browning
Provide bright, indirect light for at least 6-8 hours daily; a south or west-facing window is often ideal indoors. If natural light is insufficient, consider using an LED grow light.
Water your aloe deeply but infrequently, allowing the top third of the potting soil to dry completely between waterings. This often means watering every 2-3 weeks, or less in winter. Ensure the pot has drainage holes and use a well-draining succulent or cactus mix to prevent waterlogging.
Keep your aloe in a stable temperature range, ideally between 55°F and 80°F (13°C to 27°C), avoiding sudden fluctuations or prolonged extremes. Protect outdoor plants from frost by bringing them indoors when temperatures drop below 50°F (10°C). Fertilize sparingly, if at all, only during the growing season with a diluted houseplant formula, as aloes do not require extensive nutrients.