Q.

Why are the leaves on my citrus trees yellow?

Natala

A.

There are several reasons for yellow leaves on citrus.

Citrus require regular feeding, watering and mulching to encourage healthy growth so that they flower and fruit.
Yellow leaves is usually an indication that the tree is lacking in nutrients such as nitrogen, magnesium and iron, applying fertiliser will help replenish missing nutrients.
Apply a balanced fertiliser such as Tui Citrus food in spring and again in late summer, early autumn.
For an extra boost, apply Epsom Salts to help correct yellow leaves, Epsom Salts is a source of magnesium which helps plants produce chlorophyll, the green pigment in leaves.
Use Tui Epsom Salts at a rate of 30g (2 tablespoons) per 1 litre of water and apply around the dripline of the tree (where the canopy extends out to).
For established trees water regularly, 2-3 times a week in very dry spells.
Mulching around the tree with a suitable plant-based mulch will help conserve soil moisture, Tui Mulch and Feed is the perfect mulch for citrus trees, apply in spring and autumn.
Citrus have fibrous surface feeding roots that don't like competing with grass or weeds for nutrients and water. Remove an area around the tree up to 50cm in diameter so that grass isn't right up around the base of the trees and mulch around the area once the grass is removed.