Jade plants (Crassula ovata) are popular succulents known for their thick, glossy leaves. Brown spots on their foliage are a common concern, signaling various underlying issues from environmental stress to pests or disease. This guide identifies the causes of brown spots and provides solutions to restore your jade plant’s health.
Diagnosing Brown Spots
Diagnosing brown spots on a jade plant requires a thorough visual inspection. Observe the spots’ location, noting if they are on older leaves, new growth, or along edges. The texture provides clues: mushy, dry, crispy, or scabby. Pay attention to color variations, from light tan to black. Look for other symptoms like wilting, leaf drop, shriveling, or sticky residue. These details help narrow down potential causes.
Common Causes and Solutions
Overwatering and Root Rot
Overwatering often causes brown spots and root rot. Excess water, especially in poorly draining soil, deprives roots of oxygen. This appears as brown, mushy, or black spots, particularly on lower leaves, with possible wilting or a soft, swollen stem. Leaves might also appear yellow and translucent before turning brown. To address this, reduce watering frequency, allowing the soil to dry completely between sessions. If root rot is suspected, inspect the roots, trim any black or mushy parts with sterilized shears, and repot in fresh, well-draining succulent soil. Use a pot with drainage holes.
Underwatering
Underwatering also causes brown spots, appearing as dry, crispy, or shriveled areas, often at leaf tips or edges. Leaves may become thin and wrinkled. If the soil is bone dry and leaves shrivel, provide a deep, thorough watering, allowing water to drain completely from the pot. Consistent watering, allowing soil to dry between sessions, will help leaves recover.
Sunburn
While jade plants enjoy bright light, sudden intense direct sunlight causes sunburn. This results in bleached, crispy, or scorched brown spots on exposed leaves, which may initially appear as pale patches before turning brown. Move the plant to bright, indirect light or provide shade during peak sun. Gradually acclimate plants to higher light levels. Severely sunburned leaves will not heal and should be removed to encourage new growth.
Pests
Pests like mealybugs and scale insects cause brown spots by feeding on sap. They appear as small, white, cottony masses or brown bumps on leaves and stems. Their feeding results in discolored, scabby brown spots or speckled areas, often on the underside of leaves. Regularly inspect your plant for pests. Remove visible pests with a rubbing alcohol-dipped cotton swab, or use insecticidal soap or neem oil for larger infestations. Isolate infested plants to prevent spread.
Fungal Issues
Fungal issues can occur in jade plants, especially with high humidity or poor air circulation. Infections may appear as spreading brown or black spots, sometimes with a soft texture or distinct margins. Sooty mold, a black growth, can also result from sap-sucking pests. To prevent fungal problems, ensure good air circulation and avoid overwatering. Prune affected leaves with sterilized tools to prevent spread. Improving environmental conditions, like reducing humidity, can help.
Cold Damage
Low temperatures can severely damage jade plants, causing brown or black spots. Cold damage results in dark brown to black, mushy spots or blackened leaves, often after sudden temperature drops. The water inside plant cells can freeze and rupture, making affected leaves soft and squishy. Move the plant to a warmer environment immediately, ideally between 65°F and 75°F, avoiding drafts or direct heat. Prune away any damaged parts to encourage recovery.
Fertilizer Burn
Over-fertilization causes brown spots, known as fertilizer burn. This appears as crispy brown leaf edges or general browning, sometimes with a white crust on the soil surface due to salt accumulation. Too much fertilizer can draw moisture from the plant’s roots, leading to dehydration. If suspected, flush the soil with plain water to remove excess salts. Dilute future fertilizer applications to half or quarter strength, as jade plants are sensitive. Fertilize only during the active growing season, ensuring the soil is moist beforehand.
Preventing Brown Spots
Preventing brown spots requires consistent basic care.
Watering: Allow soil to dry completely between waterings to prevent both over and underwatering.
Soil and Drainage: Use well-draining succulent soil and pots with drainage holes.
Light: Provide bright, indirect sunlight, gradually introducing plants to new light environments to prevent sunburn.
Pest Inspection: Regularly inspect for pests to allow early intervention.
Fertilization: Apply fertilizer sparingly and only during the growing season.