I have two informal maple bonsai (i.e., seedlings that I dug up from the garden and potted), both of which have some browning on their leaves:

enter image description here

enter image description here

Preliminary research indicates that this could be because of overwatering, underwatering, insects, fungi, or malnutrition (i.e., a lack of fertilizer). That's a wide field. Moreover, there's also a ficus that is doing just fine, with no browning at all.

  • The fact that the ficus is OK suggests that it's parasitic, since they're all on the same watering regimen.
  • There's adequate drainage and I check the soil before watering, so overwatering is unlikely to be the problem.
  • However, the browning only appears on the older leaves, not the newer ones, so maybe it's part of the lifecycle of the leaves?

But all that is wild speculation. Can anyone help me narrow this down?

1 Answer 1


Inspect the leaves closely with a magnifying glass - I'm seeing what might be remains of webbing and even what might be a small, pale caterpillar, first picture, on the large, browning leaf. Check the undersides too - if what I think I can see is right, you may have had a light infestation of moth larvae, but likely most have turned into moths now and left... Moth larvae grazing on the leaf surface would explain the damage, but have a good look.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.