The "marshmallow white things" are almost certainly mealy bug. Blast them
off with your hose, paying particular attention at all joints. If that
fails, spray with white oil, which will probably do the job on the gardenias
too. You might also consider cutting back on watering for a while.

"Tristan" wrote in message
.. .
We have a North/South aligned path running from our front door along the
side of the house to the garage, it is shaded on both sides and the
Northern
end so it gets very little sunlight. The Orange Jessamines are doing
fantastically but everything else seems to be covered in a white fluffy
fungus. The roses are especially affected, I know its too dark for them
really but we would like them to stay. The Gardenias are also affected,
however the very sick gardenias are the ones closest to a rendered brick
wall, which actually acts as a retaining wall for about 40 cm of next
doors
land. I was wondering perhaps if excessive lime was leaching out of the
wall
and into the soil. The Gardenias also have a brown sooty coating, plus
what
I think is scale, and occasionally those little marshmallow white things.
Can any one help? We are in Perth.


Tristan