How can I troubleshoot yellowing leaves?
Written by
Paul Reynolds
Reviewed by
Prof. Martin Thorne, Ph.D.Yellowing leaves indicate something is wrong with your indoor herb garden, requiring quick action. This is a common symptom of either overwatering/or a nutrient deficiency. It is essential to identify the cause of the yellowing to correct the issue effectively. Check the soil's moisture level and recent changes in care to determine the problem. For example, my basil recovered after I addressed the issues of overwatering and a nutrient deficiency.
Moisture Check
- Insert finger 2 inches into soil
- Soggy soil indicates overwatering
- Bone-dry soil suggests underwatering
- Check pot weight for confirmation
Nutrient Analysis
- Examine yellowing pattern on leaves
- Uniform yellowing suggests nitrogen deficiency
- Vein-centered yellowing indicates iron lack
- Review fertilization history
Environmental Review
- Assess recent light changes
- Check for temperature extremes
- Identify pest presence
- Note pot size and root crowding
Herbs that are overwatered will require attention immediately! The first step is to stop watering completely until the soil has dried. Remove the plants from their pots to cut away any brown, rotten roots. Repot the herbs in a fresh, well-draining potting mix. My mint plant survived four or five days without any water and is now thriving.
A sign of nitrogen deficiency is overall yellowing, predominantly on older leaves. Treat nitrogen deficiency with a liquid fish emulsion fertilizer diluted to half strength. Results will typically manifest in a matter of days, as green will return and the foliage will fully recover. My parsley was completely transformed after two applications of the fertilizer.
Crop compromised leaves to restore the plant's energy levels. Use sterile scissors to cut the leaves above healthy nodes. Never remove more than one-third. My basil has produced a larger amount of growth after trimming, as the pruning was performed appropriately. Cleaning tools used in the process help prevent the spread of pathogens.
Use care adaptations to avoid recurrence. Water whenever the top inch of soil is dry to the touch. Fertilize regularly during vegetative and flowering stages. Check that the light exposure is consistent. My herbs stay healthy with these simple changes in habits.
Read the full article: 7 Essential Indoor Herb Garden Secrets
