What cause mould on Rosella plants?
I have several rosella plants growing. They now have a white mould at the joints of the leaves and it is killing them. Regards, Merv.
What a shame your rosella bushes are being damaged by this white mould. Because of the enormous amount of rain we have experienced this year and also the humidity that always seems to be present during the summer months, it is a perfect environment for fungus to grow. Powdery mildew is a fungus that grows on plants and crops in humid weather. The fungus usually starts out on the leaves as a small dot and then develops to cover the entire leaf during favourable conditions. To control this fungus, you can spray with a product called Lime Sulfur. Use it at the rate of 10mls per 1 litre of water and thoroughly water all parts of the plant. Be careful not to spray when the temperature are over 32 degrees C. It might also be advisable to check the plants for pests such as mealy bugs. This insect also thrives in warm, moist conditions. They congregate around buds, where two pieces of fruit touch or where leaves overlap. These insects are oval in shape and have white waxy threads around their bodies. If this pest is present, spray with Yates Nature's Way Vegie & Herb Spray Concentrate.
Answered: 10 Mar, 2012