Sooty Mould - Jasmine

NaseemBanu

Hi, 

I've read that spraying Neem oil followed by a solution of dish soap on plants which have sooty mould is effective. 

I have a beautiful Jasmine Trachelospermum which is about 9 years old; it has developed this unsightly mould. My understanding is that this is common for plants located in sheltered positions against walls and under eaves.

I would welcome advice from people on this forum beforer I use the Neem oil and dish soap method.

Obelixx

Sooty moulds are usually a sign that you have sap sucking insects infesting your plant and its their sugary secretions which feed the moulds.

You should be able to rinse off the worst of the mould with a good blast form a hosepipe with a spray nozzle attached - not a pressure washer!   Thereafter, you need to treat the infestation of pests which means checking to see which they are so you choose the appropriate treatment.

Just spraying with a soapy solution may not be effective for some and will certainly harm beneficial predators such as ladybirds, lacewings, hoverflies etc which will eat aphids.

I suggest you have a read of this info from the RHS before going any further - https://www.rhs.org.uk/advice/profile?pid=770 

BobTheGardener

I agree with Obelixx and strongly suspect the underlying cause is scale insects, probably cushion scale.

NaseemBanu

Many thanks for your replies Obelixx and Bob. Very helpful.