Pest or disease on lemon tree

joneso192 · February 2019

Hi, so IV owned a lemon tree for about 5 years, it's lived in the greenhouse for 2-3. Every year a dirty sediment appears on the leaves, at first I thought it was normal, but after wiping the leaves and cutting off bad ones, it returned within a few months. Can anyone identify the problem? This dirt only appears on the top of the leaves, but I almost lost the tree as last year it was so bad. Now spring is on the horizon and it's back.

I have noticed pests on the underside of the leaf, almost like limpets. Could this be the problem?

Obelixx · February 2019

The black stuff is sooty mould growing on honeydew secreted by soft scale insects. Both are a symptom of poor growing conditions. You could try washing off all the sooty mould deposits but the insects will be hard to shift so the mould will reappear.

Have a read of this info from the RHS and then decide whether to treat the problem or replace the plant but do make sure the greenhouse has a thorough clean either way - https://www.rhs.org.uk/advice/profile?pid=788

joneso192 · February 2019

Obelixx said:

The black stuff is sooty mould growing on honeydew secreted by soft scale insects. Both are a symptom of poor growing conditions. You could try washing off all the sooty mould deposits but the insects will be hard to shift so the mould will reappear.

Have a read of this info from the RHS and then decide whether to treat the problem or replace the plant but do make sure the greenhouse has a thorough clean either way - https://www.rhs.org.uk/advice/profile?pid=788

Thanks friend, that's a great help 🙂

Pest or disease on lemon tree

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