Question From:
ALAN ROGERS in greenmount, perth WA
Nature of problem:
leaves exhibit two (2) problems. 1. galls on the underside of the leaves and a ‘buckling’disfigurment of the leaf, and (2) mature leaves are covered with a black soot mould. During the summer, a ‘juice’ residue is excreted from the lilly pilly psyllid (I assume) and forms a sticky carpet under the tree. The paving under the tree also becomes stained by the black soot.
Type of Plant (if known):
lilly pilly ,Waterhousea floribunda – dark green shiny leaves, soft fibrous cream flowers, red/pink cherry/berry fruit
Symptoms of Plant Illness (please try NOT to diagnose your problems yourself):
leaves exhibit two (2) problems. 1. galls on the underside of the leaves and a ‘buckling’disfigurment of the leaf, and (2) mature leaves are covered with a black soot mould
Soil Type (e.g. sandy, clay or loam) OR Potting Mix Type:
clay
How often do you water the plant:
never – or as often as I water the lawn
How many hours of sunlight does the plant get each day:
all day sunlight
What type of plant is it:
tree – age is greater than 35 years. The tree was a mature tree approx 10m when I purchased the property 35 yrs ago. Age probably 50 years. Tree height is now approx 20 + metres
How long since you planted it:
35+ years
Have you fertilised? If so, with what and when:
no
Is the plant indoors or outdoors:
outdoor
What other treatments have you given the plant:
last summer I spayed with a systemic (rogor) and a surface insecticide
Upload photo if available:
Other Comments:
I have checked the BBY fact sheets and other sites for information. Information on the lilly pilly psyllid is readily available. I have not been able to find out any information on the black sooty covering on the upperside of the leaf (mould) nor any information on the sticky liquid that is excreted.
Any advice would be very much appreciated.
Answer: Hi Alan, Waterhouseas are VERY prone to psyllid damage and the black sooty mould grows in its excrement. Lilly pillies HATE WA. Dry summers are horrible for these rainforest trees. Use a native plant fertiliser and Seasol Super Soil Wetter to get around water-repelling soils. Then accept the result. Good luck, Don
