diseased leaves - Knowledgebase Question

Santa Maria, Ca
Avatar for jerrilynneat
Question by jerrilynneat
September 7, 2009
I have a Mexican Lime tree that is in a planter, it was thriving until all of the sudden I noticed some black (looks like mold) on the leaves. Would it help if I took it out of the pot and planted it in the ground? Please advise. Thank you.

Answer from NGA
September 7, 2009
If the black substance can be wiped off the leaves with a soapy cloth, the problem is called sooty mold. The substance is appearing because your tree has a population of insect pests. Aphids, scale insects and mealybugs feed on the fluids of the leaves and stems and excrete a sticky substance called honeydew. This substance coats the tops of the leaves directly below where they are feeding. As the honeydew ages, it turns black. Carefully inspect your tree for insect pests. Aphids can be controlled with insecticidal soap, scales and mealybugs can be dabbed with a Q-Tip dipped in rubbing alcohol. Once you control the insect pests the sooty mold will not reappear. Best wishes with your lime tree.

You must be signed in before you can post questions or answers. Click here to join!

« Return to the Garden Knowledgebase Homepage

Member Login:

( No account? Join now! )

Today's site banner is by Murky and is called "Lilac 'Declaration'"

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.