Why Your Citrus Leaves Turn Yellow and How Magnesium Can Help
If you've noticed your citrus trees looking a bit under the weather with yellowing leaves, you're not alone. This common issue often signals a magnesium deficiency, and the good news is that it's easily treatable with the right approach. Epsom salt is a natural, cost-effective solution that can restore your trees to vibrant health.
Understanding Magnesium Deficiency in Citrus Trees
Citrus trees rely on magnesium to produce chlorophyll, the pigment that gives leaves their healthy green colour. When magnesium levels drop, leaves begin to yellow while the veins may remain green—a telltale sign of deficiency. This often happens in older leaves first, as the tree redirects remaining magnesium to new growth.
Factors that can deplete magnesium include heavy rainfall, sandy soils, and overuse of potassium-rich fertilisers. The good news is that epsom salt provides an immediately available form of magnesium that your trees can absorb quickly.
How to Apply Epsom Salt Spray
Foliar spraying is one of the most effective ways to treat magnesium deficiency. This method allows your citrus leaves to absorb magnesium directly, often showing improvement within weeks.
Basic Epsom Salt Spray Recipe:
- Dissolve 1 tablespoon of epsom salt in 1 litre of water
- Stir until fully dissolved
- Pour into a spray bottle
- Apply in early morning or late evening to avoid leaf burn
- Spray both the tops and undersides of leaves until lightly coated
- Repeat every two to three weeks during the growing season
For larger trees or severe deficiency, you can also water epsom salt directly into the soil around the base of your tree. Use 1 to 2 tablespoons per tree, mixed into the soil about 30 centimetres from the trunk.
Best Practices for Results
Timing matters when treating citrus deficiency. Spring and early summer are ideal, as trees are actively growing and can best utilise the magnesium boost. Avoid spraying during the hottest part of the day, and skip application if rain is forecast within 24 hours.
Monitor your trees regularly. Healthy new growth should emerge within a few weeks, with older leaves gradually improving as well. Be consistent with applications—magnesium deficiency doesn't resolve overnight, but with regular treatment, you'll see noticeable greening.
Preventing Future Deficiency
Once your citrus trees have recovered, maintain their health with occasional epsom salt applications. A single application in spring and another in mid-summer can prevent deficiency from returning. This simple step keeps your trees lush and productive year after year.
Epsom salt is affordable, non-toxic, and safe for organic gardening, making it the go-to choice for citrus growers across New Zealand. Your trees will thank you with vibrant foliage and abundant fruit.