Question From:
in Carrickalinga , SA South Australia
Nature of problem:
Young leaves curl and blacken, older leaves once grown appear chewed
Type of Plant (if known):
Hibiscus tiliaceus rubra (Red Cottonwood)
Symptoms of Plant Illness (please try NOT to diagnose your problems yourself):
Young leaves curl and blacken, older leaves once grown appear chewed
Soil Type (e.g. sandy, clay or loam) OR Potting Mix Type:
Sandy
How often do you water the plant:
Not at all during winter, weekly to fortnightly in summer
How many hours of sunlight does the plant get each day:
All day
How long since you planted it:
Three years
Have you fertilised? If so, with what and when:
Occasional seasol, dynamic lifter/blood and bone in Spring
Is the plant indoors or outdoors:
Outdoors
Is the plant in a pot or in the ground:
Ground
What other treatments have you given the plant:
White oil this season, last year I tried a number of organic bug sprays and finally confidor – nothing seems to assist
Upload photo if available:
Other Comments:
I have searched these trees (I have four) for hours trying to find a pest/bug on them to no avail including at night by torchlight. I am uncertain what to try next as all new growth appears blackened on the edges, curls slightly then opens into a grown leaf with half of it missing.
Thank you for your help,
Jenny
Answer:
Hi Jenny, It may be Hibiscus beetle. If your plant is healthy, it should repel pests all by itself. Hibiscus tiliaceus is native to islands throughout the pacific area. I don’t know your area, but I suspect that watering is the issue. SA is a complex issue for watering. Get a soil wetting agent such as Seasol Super Soil wetter, or Saturaid. Dig in lots of compost and dig small holes with a trowel to see if your soil is improving in soil water retention. As the soil and watering improves, the plant will do better and better. Toxic sprays are not the answer. Don
