Aloe plants, popular for their appearance and medicinal properties, sometimes show leaves turning red, orange, or purple. This color change indicates environmental stress, signaling the plant needs attention.
Understanding Aloe Reddening
The change in an aloe plant’s coloration, specifically to reddish or purplish hues, is primarily due to the production of pigments called anthocyanins. These pigments are similar to those responsible for the vibrant colors seen in autumn leaves. An aloe plant produces anthocyanins as a natural protective mechanism when it is exposed to conditions it perceives as stressful. This process is akin to a plant developing a “suntan” to shield its chlorophyll from potential damage. The presence of these pigments indicates that the plant is working to protect itself, suggesting that its environment needs adjustment.
Sun Stress and Redness
Identifying Sun Stress
When an aloe plant receives an excessive amount of direct, intense sunlight, its leaves may begin to turn a uniform reddish-brown or deep orange. This discoloration often affects the entire plant or the parts most exposed to the sun. The leaves might also develop a hardened, somewhat leathery texture, indicating that the plant is attempting to protect its internal moisture and tissues. This symptom is especially pronounced if the aloe was previously in a lower light environment and then suddenly moved to a very bright location.
Adjusting Light Conditions
To alleviate sun stress, it is beneficial to relocate the aloe plant to a position that receives indirect, bright light. This could mean placing it a few feet away from a sunny window or using a sheer curtain to diffuse intense sunlight. If the plant is outdoors, moving it to a spot with morning sun and afternoon shade can be effective. Gradually acclimating an aloe to brighter conditions over several weeks can also help prevent sudden sun stress and the associated reddening.
Temperature Extremes and Redness
Identifying Temperature Stress
Aloe plants can exhibit reddening in response to both excessively hot and cold temperatures. Cold stress often results in a bluish-red tint to the leaves, and in severe cases, prolonged exposure to freezing temperatures can cause mushy, damaged spots. Conversely, heat stress typically leads to a more intense, vibrant red coloration, sometimes accompanied by a generally withered or dehydrated appearance. The plant’s overall turgidity might also decrease under sustained high temperatures.
Managing Temperature Fluctuations
Maintaining a stable temperature range is important for an aloe plant’s well-being. Aloe vera thrives in temperatures generally between 60 to 80 degrees Fahrenheit (15 to 27 degrees Celsius). It is advisable to move the plant away from drafty windows during cold months or from direct heat sources like radiators and air conditioning vents. For outdoor aloes, providing shade during peak summer heat or bringing them indoors before the first frost helps protect them from temperature extremes.
Watering Issues and Redness
Identifying Water Stress
Insufficient watering, or prolonged drought, can also cause an aloe plant to turn red. When an aloe is severely underwatered, its leaves may appear thin, shriveled, and often develop a reddish or purplish hue as it attempts to conserve moisture. This differs from overwatering, which typically leads to yellow, mushy leaves and root rot. The reddening from underwatering is a signal that the plant’s water reserves are critically low, prompting a stress response.
Correcting Watering Habits
Proper watering involves allowing the soil to dry out completely between waterings, then thoroughly saturating it. This “soak and dry” method ensures the roots receive adequate moisture without sitting in soggy conditions. Always use a pot with drainage holes to prevent water accumulation at the bottom. Before watering, check the soil moisture by inserting a finger about two inches deep; if it feels dry, it is time to water again.
Nutrient Deficiency and Redness
Identifying Nutrient Problems
While less common than environmental stressors, certain nutrient imbalances can contribute to an aloe plant’s reddening. Deficiencies in specific macronutrients like phosphorus or micronutrients such as magnesium can sometimes manifest as reddish or purplish discoloration. This discoloration often appears along the leaf tips or margins, or as an overall dulling of the green. This type of reddening usually appears more subtle and localized compared to the uniform, vibrant red caused by sun exposure.
Supplying Essential Nutrients
Aloe plants are low feeders and don’t need frequent fertilization. During their active growing season (spring and summer), a very diluted liquid fertilizer can be beneficial. Use a balanced houseplant fertilizer at one-quarter strength every two to three months. Over-fertilization can cause more harm than good, leading to nutrient burn and other issues.
General Aloe Care for Prevention
Preventing aloe reddening involves consistent application of good cultural practices. Providing a well-draining potting mix, ideally formulated for succulents or cacti, is fundamental for root health. Choosing a pot that allows for proper drainage is equally important to avoid waterlogged conditions. Regularly inspecting the plant for early signs of stress, such as slight changes in leaf color or texture, enables prompt adjustments. Adjusting care routines seasonally, such as reducing watering frequency in winter, contributes to maintaining a consistently healthy and vibrant green aloe.