Fix Yellow Leaves: Nitrogen, Iron & Magnesium

Why are my plant leaves turning yellow?

Yellow leaves are one of the most common signs that a plant is under stress. While natural ageing can cause older leaves to yellow, widespread discolouration may indicate issues such as nutrient deficiencies, inconsistent watering, poor drainage or unsuitable growing conditions.

Identifying the underlying cause is the first step towards restoring healthy, vibrant foliage.

Common causes of yellow leaves

• Nitrogen deficiency affecting older leaves.
• Iron deficiency causing yellowing between leaf veins on new growth.
• Magnesium deficiency resulting in interveinal chlorosis.
• Overwatering or poor drainage reducing root health.
• Environmental stress caused by temperature, light or transplant shock.

Choosing the right product

Our Fix Yellow Leaves collection includes products designed to support healthy plant nutrition and correct common deficiencies.

• Nitrogen-rich fertilisers: Help support lush green leafy growth.
• Iron supplements: Suitable where iron deficiency is identified.
• Magnesium sources: Products containing Epsom salts, Kieserite or K-Mag can help address magnesium deficiencies.
• Organic nutrition: Fish hydrolysate and soybean meal provide natural nutrient sources for ongoing plant health.

Tips for preventing yellow leaves

• Water consistently without leaving roots waterlogged.
• Feed plants with a balanced fertiliser appropriate for their growth stage.
• Ensure your growing medium drains well.
• Monitor pH where appropriate, as it can influence nutrient availability.
• Inspect plants regularly so issues can be addressed early.

Learn how to diagnose yellow leaves

Not every yellow leaf has the same cause. If you're unsure what's affecting your plants, explore our guide on diagnosing yellow leaves to better understand the symptoms of common nutrient deficiencies and choose the most suitable solution for your garden.

Shop products to fix yellow leaves at Dr Greenthumbs

Browse our Fix Yellow Leaves collection for quality fertilisers, organic amendments and nutrient supplements that help support healthy, green foliage. Whether you're correcting a deficiency or maintaining vigorous plant growth, you'll find trusted solutions for Australian gardeners.