The African Milk Tree (Euphorbia trigona) is a distinctive succulent known for its upright, architectural stems. As a popular indoor plant, leaf drop is a common concern. Understanding why this happens is key to maintaining a healthy plant.
Is African Milk Tree Leaf Drop Normal?
Some leaf drop is natural. Older leaves, especially at the plant’s base, may yellow and fall off as it matures. This is a normal part of its life cycle.
During winter, African Milk Trees often shed many leaves as they enter dormancy. These leaves typically regrow in spring. Minor leaf loss can also occur due to acclimation stress when the plant is moved or repotted. However, excessive, sudden leaf drop, or if accompanied by discolored or mushy stems, indicates an underlying problem.
Common Reasons for Leaf Loss
Watering Imbalances
Watering issues are frequent culprits. Underwatering causes leaves to become dry, crispy, and shriveled as the plant dehydrates. Overwatering can lead to root rot, manifesting as soft, yellowing, or mushy stems, which causes leaves to drop. Overwatered soil often feels waterlogged and may have a musty smell.
Insufficient Light
African Milk Trees prefer bright, indirect light, though they tolerate some direct sunlight. Inadequate light may cause the plant to shed lower leaves to conserve energy. Insufficient light can also lead to weak, stretched growth.
Temperature Fluctuations
Sudden or extreme temperature changes stress the African Milk Tree, leading to leaf loss. They thrive between 15-29°C (59-85°F) and do not tolerate cold drafts or temperatures below 13°C (55°F). Temperatures below 4°C (40°F) can be damaging, causing leaves to drop defensively.
Environmental Shock
African Milk Trees can experience shock and leaf drop from significant environmental changes. This occurs after repotting, moving the plant to a new location with different light or temperature, or prolonged exposure to intense direct sunlight without acclimatization. The plant needs time to adjust.
Pests or Diseases
Pests or diseases can contribute to leaf shedding by weakening the plant. Severe infestations of spider mites, mealybugs, or scale insects can sap vitality, leading to yellowing leaves and eventual drop. Fungal infections, often exacerbated by overwatering, can cause black or brown spots on stems and leaves, leading to plant decline and leaf loss.
How to Diagnose and Address Leaf Drop
Observing specific symptoms helps pinpoint the cause. If leaves are dry and crispy, it suggests underwatering. Gradually reintroduce water by giving small amounts daily for a week to avoid shock. If leaves are soft, yellow, or mushy, overwatering is likely. Immediately stop watering and inspect for root rot.
To address light issues, move your plant to a location with bright, indirect light, such as near a south-facing window. Protect the plant from cold drafts by moving it away from windows or air conditioning units, ensuring temperatures remain within its preferred range. For environmental shock, allow the plant time to acclimate, reducing further stressors. If pests are suspected, inspect the plant for visible signs and treat localized infestations by wiping them off with a cotton swab dipped in soapy water or applying insecticidal soap.
Proactive Care to Prevent Leaf Loss
Maintaining a consistent care routine prevents future leaf drop.
- Water the plant thoroughly only when the soil has completely dried out; they are drought-tolerant succulents. Allowing the soil to dry between waterings prevents root rot.
- Provide ample bright, indirect light, ideally with a few hours of direct sun, but avoid intense midday sun that can scorch leaves.
- Ensure stable room temperatures, avoiding sudden drops or cold drafts.
- Plant your African Milk Tree in well-draining soil, such as a cactus or succulent mix, and use a pot with drainage holes to prevent waterlogging.
- During the growing season (spring and summer), an occasional feeding with a diluted liquid fertilizer supports healthy growth.
- Regularly inspect your plant for early signs of stress, discoloration, or pests to address issues before they become severe.