I thought this could be an iron deficiency at first but my tree has yellow spots rather than the yellowing all over as I have seen on pics online. I tried treating the tree with white oil in case there was a pest issue but nothing changed. Any ideas as to what it could be?
19 December 2013 09:21 AM
Hi Lindsey,
The yellow patches may be caused by scale. Often the scale can be found on the underside of the leaf and can be scratched off with a fingernail. Applying PestOil regularly will help.
To improve the general health of the mandarin apply fertiliser in spring and autumn. Try Yates Dynamic Lifter Soil Improver & Plant Fertiliser. It's certified organic and will help create a nutrient rich soil for better root growth, stronger plants and more flowers and fruit! It can be used on gardens all year round, including native plants.