Yellowing leaves on your citrus trees can be concerning, but with the right approach, you can restore their health and vibrancy. Here’s how to tackle the most common causes:

1. Iron Deficiency (Chlorosis)

If your citrus leaves are turning yellow with green veins, they might be suffering from iron deficiency, known as chlorosis. This is particularly common in areas with alkaline soils, like parts of South Australia.

Solution: Apply iron chelates according to the manufacturer’s instructions. For the best results, mix the solution and apply it directly to the soil using a watering can around the base of the tree. You could start to see the benefits of this in as little as two weeks, although it’ll take a few months for your plant to fully recover if the deficiency is more severe.

2. Magnesium Deficiency

Magnesium is essential for chlorophyll production. A lack of magnesium can lead to yellowing leaves, especially during autumn when citrus trees are producing fruit.

Solution: Use Epsom salts (magnesium sulfate) as a soil drench. Dissolve the recommended amount in water and apply it to the soil around the tree. Already-yellowed leaves will stay that way, but the good news is that new growth should come in looking vibrant in around a month!

3. Watering Issues

Overwatering

Excess water can lead to root rot, depriving your citrus tree of essential nutrients and causing yellow leaves.

Solution: Ensure your tree is planted in well-draining soil. Water the tree deeply but infrequently, allowing the topsoil to dry out between waterings.

Underwatering

On the other hand, insufficient water can also stress the tree, causing yellowing leaves.

Solution: Increase watering frequency, ensuring the water penetrates deep into the soil to reach the roots.

​​Bonus Tip: How to Tell if It’s Overwatering or Underwatering

Yellow leaves can look the same whether your citrus is getting too much or too little water, but a few simple checks can help you figure it out. Stick your finger about 5 cm into the soil; if it feels soggy, overwatering is likely the culprit; if it’s dry, your tree needs a deeper drink. 

Check the pattern of yellowing too: overwatered trees often show yellowing on older leaves that feel soft, while underwatered trees usually have yellowing that’s more even, with leaves that may feel crisp or droopy during the heat of the day. Adjust your watering accordingly to keep your citrus thriving.

4. Pests and Diseases

Pests like aphids and fungal infections can damage citrus leaves, causing them to yellow and drop prematurely.

Solution: Regularly inspect your tree for signs of pests. If you spot any, use appropriate pest control treatments, such as insecticidal soap or neem oil, and remove affected leaves.

Quick Tips for Citrus Care

• Apply mulch around the base to retain moisture and regulate soil temperature.
  
• Prune dead or yellowing leaves to improve airflow.
  
• Fertilize during the growing season with a balanced citrus fertilizer.
  
• Protect your tree from strong winds and frost.

Get the Experts Involved

Need help with your citrus tree care? Contact your local Jim’s Mowing expert today for a free, no-obligation quote.