Damaged Leaves: Common Causes and How to Deal With Them

If you notice spots, curling, discoloration, or holes on leaves, there are a few common reasons—ranging from pests to environmental stress. This guide breaks down the possible causes into two main groups to help you pinpoint the issue and take action. Here’s what to look for:

• Older leaves with yellowing, browning, or spotting often point to nutrient imbalances, natural aging, or long-term environmental stress such as poor airflow or inconsistent nutrient delivery.

• Newer leaves showing curling, wilting, stunted growth, or dark rot may suggest moisture buildup, fungal infections, or bacterial diseases. This is more common in tightly spaced fogponic environments with poor air circulation.

  • Excessive humidity and stagnant air can lead to leaf spot, powdery mildew, or damping-off, especially in seedlings and young herbs.

• A single damaged leaf is often just a result of mechanical damage, early nutrient imbalance, or a minor light/humidity shift.

• Widespread symptoms across one plant or multiple pods can indicate:

  • A fogger or nutrient delivery malfunction

  • Light spectrum or intensity issues (e.g., burn or stretching)

  • Inadequate air circulation, leading to a buildup of pathogens

• Look for alerts or abnormal readings: low water or nutrient levels, temperature spikes, or fan/fogger failures.

• Confirm the system matches your current plant stage (e.g., blooming mode off for leafy greens).

• Note any recent changes: moving pods, temperature shifts, or beginning of flowering can all stress plants.

• A individual leaf is yellowing, crispy, heavily spotted, curling, or wet with moldy patches.

• Damaged leaves are still drawing energy from the plant. Use clean scissors to remove the entire leaf at the base of the stem.

• Regular pruning keeps airflow better and helps the plant direct energy toward new growth.

• More than 50% of the plant is affected and growth is severely stunted or leaves show soft rot, widespread black lesions, or stem collapse.

• The plant is showing signs of systemic disease (affecting all new growth) or is beginning to rot at the base.

• There is a recurring issue across multiple pods, such as:

  • Persistent mold or algae buildup on multiple surfaces

  • Foul smell, indicating root rot or bacterial spread

  • Clogged fogger or biofilm in nutrient lines

• This might signal a systemic contamination or a need for a fresh start.

• Leaves feel soft/slimy or darken at the tips: likely a sign of over-saturation or disease.

• Surface condensation, fog droplets pooling, or mossy growth on pods: reduce humidity and check for airflow blockages.

• White powdery coating, especially on herbs: remove affected leaves and increase airflow by pruning dense plants.