I've been trying to clean the black stuff off my potted lemon tree from a white fly infestation. Now I have ants, what is attracting them? The leaves are turning yellow, my tree does not look happy, what can I do?

• The ants are on your citrus because of the white fly which are sap sucking insects that excrete a honey dew when they feed on plants, the ants are feeding on the honeydew.
• The black sooty mould is a fungus that lives on the honey dew. It does not harm the plant, but reduces vigour and weakens the plant, as do the sap sucking insects and so the plant is getting weak and the leaves starting to yellow.
• There may still be other insect pests on your tree if the ants are still present.
• Spray with a botanical plant spraying oil to smother the insects and the sooty mould will wash off over time once the insects are controlled. Your local garden centre or hardware store will be able to recommend a suitable control for sap sucking insects such as white fly and scale insect.
• Your plant will benefit from feeding, for pots and containers use a controlled release fertiliser such as Tui Fruit, Citrus, Tree & Shrub controlled release fertiliser, apply in spring and again in late summer, early autumn. 
• Weekly applications of Tui Organic Seaweed Plant Tonic will also help your plant recover, mix 60ml in a 9 litre watering can and apply as a soil drench.
• Regular watering will also help improve the overall health of your tree, in spring and summer water plants in pots at least 2-3 times a week with 5 litres of water per plant.
• To keep your plant well nourished, apply Tui Citrus & Fruit Superfood liquid fertiliser to improve overall growth and correct nutrient deficiencies such as magnesium deficiency which causes yellowing leaves.

Read the Tui Citrus Grow Guide

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