I was up in the 3/4 acre woodland garden I look after the other day, and cutting back a camellia which was overhanging the pathway quite badly (this is the kind of thing I spend most of my time doing in this particular garden – the amount of green waste I remove from there has to be seen to be believed!)
I noticed pretty quickly that behind the curtain of fresh green leaves there was a problem. All the older leaves were covered in a sticky, black sooty mould, which not only looked nasty but also couldn’t have been doing the shrub much good.
I wasn’t quite sure myself what was causing it – I thought aphids of some sort, since this is what causes it on roses (the aphids secrete honeydew, which drips on the leaves below and is consequently colonised by the fungal sooty mould). I was a bit unsure about this since I’ve never heard of aphids attacking camellias to any great degree.
Anyway – I came back and looked it up, and thanks to the dear old RHS I discovered we almost certainly have not aphids, but Camellia cushion scale.
I have to go back and check whether there are yellow-brown scale insects near the veins (or indeed “white waxy egg masses”). But everything else fits.
The good news is, this is just the right time of year to control it. I’m going to have to spray; I’ll try the organic version first (Growing Success Bug Killer or Vitax Organic 2in1) and if that doesn’t work, I’ll zap it with the very un-environmentally friendly Provado. My client tells me he has a backpack sprayer in his garage (the shrub is about 15ft tall) – so time to tog up and do battle!