Question
I have a Black Rose variety of Camellia which has 'soot' like powder on the leaves with some of the leaves curling at the edges an brown.  I suspect the curling leaves have been hurt by the frosty conditions we experienced this winter.  However, could you please give me some indication what the 'soot' is ?

Answer
Dear Sheila, Your camellia has scale, an insect that is unmoving and is located on the stems or underside of the leaves.  It will look like little bumps covering areas of your plant, but there are insects contained under the hard protective shells that are sucking sap out of your plant and causing the 'soot'.  It could also be aphids, but you would probably be more likely to notice that and scale frequently attacks camellias.  No problem, get some SunSpray (best brand) or other horticultural oil and spray the plant thoroughly, top and bottom of leaves, trunks, everything.  Spray on a sunny day and within a few hours the soot will start to flake off your plant.  The oil also covers the scale and suffocates them.  It isn't a quick fix, you will need to spray several times about 7 to 10 days apart to completely get rid of them.  You will know they are dead when they drop off.  I actually had someone who worked in a nursery tell me that the scale were dead because they weren't moving.  (They never move except as immature.) You will only know when they fall off and it will take some time.  Not having seen your camellia personally, I suppose it could be something else, but I doubt it, and in any case, the horticultural oil will cure it.  Good luck, and let me know if I can be of further assistance.  Melissa