Yellowing leaves, known as chlorosis, is a common symptom of distress in fig plants, including indoor Ficus varieties and outdoor edible fig trees. Chlorosis occurs when the leaf tissue fails to produce sufficient chlorophyll, the green pigment responsible for capturing sunlight and driving photosynthesis. This lack of chlorophyll production causes the leaf to lose its deep green color, revealing the underlying yellow hue. Pinpointing the specific cause requires careful observation of the plant’s environment and the pattern of the discoloration.
Water and Light Imbalances
Water mismanagement is the most frequent cause of fig leaf chlorosis, as the plant is sensitive to both too much and too little moisture. Overwatering starves the roots of oxygen, promoting fungal conditions like root rot, and typically causes yellowing that starts on the lower, older leaves. These waterlogged leaves often turn yellow quickly and drop. Conversely, underwatering causes the leaves to curl, become dry, and develop brown or crispy edges as the plant attempts to conserve moisture. This type of yellowing may appear throughout the plant.
Light imbalances also manifest as discoloration. Insufficient light can lead to a general pale green or yellowing of the foliage as the plant struggles to produce chlorophyll. When a fig is moved too rapidly into intense direct sunlight, the leaves can suffer from sun scald, appearing as dark or tan, scorched patches. Outdoor figs can also experience leaf scorch, where the leaf center remains green but the edges are damaged, especially when high heat and insufficient water are present.
How to Identify Nutrient Deficiencies
Nutritional problems can mimic water issues, but deficiency-related chlorosis follows distinct patterns on the leaves. Nitrogen, a mobile nutrient, is redirected by the plant from older leaves to support new growth, causing older, lower leaves to turn yellow first. If the deficiency continues, the entire plant may exhibit a lack of vigor and a lighter color.
Other deficiencies present as interveinal chlorosis, where the tissue between the veins yellows while the veins themselves remain green. Iron and magnesium deficiencies are the most common causes of this pattern, but they affect different parts of the plant. Iron is an immobile nutrient, so its deficiency appears first in the newest leaves at the top of the plant. Magnesium deficiency, which is mobile, will present as interveinal yellowing on the older, lower leaves. Regular fertilization with a balanced product can prevent these issues, which are common in container-grown figs.
Pests, Diseases, and Environmental Shock
Pests and diseases cause yellowing through direct damage or systemic infection. Sucking insects like spider mites, mealybugs, and scale feed on the plant’s sap, causing the foliage to yellow and drop. Pests are often found on the underside of the leaves and stems, appearing as fine webbing (spider mites) or white, cottony masses (mealybugs). Fungal diseases like Fig Rust and Leaf Blight start as yellow spots. Fig Rust manifests as tiny yellow spots on the upper surface with rust-colored spots underneath, leading to premature leaf drop.
Fig trees are sensitive to sudden changes in their environment, which can cause immediate leaf loss or yellowing known as environmental shock. This stress often occurs after the plant is relocated, such as moving a potted fig outdoors or bringing it inside for the winter. Abrupt fluctuations in temperature, especially cold drafts or temperatures below 50 degrees Fahrenheit, can trigger this response. The plant may shed up to 20% of its foliage, but it will usually recover once it acclimates.
Step-by-Step Rehabilitation
Addressing chlorosis begins with a methodical approach to correct the underlying stressor. First, immediately prune and remove any yellow or diseased leaves, as they will not turn green again and can harbor pathogens. If overwatering is the suspected cause, allow the top two inches of soil to dry out completely before watering again. Always ensure the pot has proper drainage to prevent root rot. If you suspect over-fertilization or mineral buildup, flush the soil thoroughly by allowing a large volume of water to run through the drainage holes.
For confirmed nutrient deficiencies, apply a balanced, quality fertilizer. Focus on nitrogen if older leaves are yellowing, or iron and magnesium if interveinal chlorosis is present. If pests are found, treat the fig with an application of insecticidal soap or neem oil, ensuring coverage on the underside of the leaves. When dealing with environmental shock, provide a stable environment with consistent light and temperature. The fig will eventually adjust and produce new, healthy growth.