Alphabetical Plant Listing

Iron Deficiency

How to Identify, Prevent, and Treat Iron Deficiency


What is Iron Deficiency?

Iron deficiency, also known as iron chlorosis, in plants refers to a condition in which the plant is unable to obtain sufficient amounts of iron from the soil, resulting in a lack of chlorophyll and yellowing of the leaves. Iron is an essential micronutrient that is necessary for the formation of chlorophyll, and its deficiency can lead to stunted growth and poor plant health.

Some plants are more prone to iron chlorosis than others. Acid-loving plants are most susceptible, but many other plants may be affected in high pH soils. Here are some example of plants affected by this deficiency: azalea and rhododendron, blueberry, citrus, gardenia, holly, magnolia, maple, oak, pear, and photinia.

What causes Iron Deficiency?

Iron deficiency can occur in soils that are too alkaline or in soils that have poor drainage or lack organic matter. Iron may also be unavailable due to high levels of other nutrients in the soil, such as manganese or zinc, which can compete with iron for uptake by the plant. Additionally, excessive watering or poor soil aeration can limit the uptake of iron.

What are the Symptoms?

Iron deficiency can cause various symptoms in plants, including:

  • Yellowing of leaves, particularly between the veins
  • Leaf veins may remain green or turn brown
  • Slow growth and stunted development
  • Reduced fruit production
  • Curling of leaves
  • Premature leaf drop

It is important to note that iron deficiency symptoms may resemble other nutrient deficiencies, such as magnesium or nitrogen deficiency. A proper soil test and plant tissue analysis can help determine the cause of the deficiency.

How to Control and Prevent Iron Deficiency?

To control and prevent iron deficiency in plants, you can take the following steps:

Plant selection: Acid-loving plants, such as azaleas, rhododendrons, and blueberries, prefer acidic soil conditions and may experience iron deficiency or other nutrient deficiencies in alkaline soils. It is important to choose the right plants for the soil conditions and to adjust the soil pH as needed to ensure that the plants can access the nutrients they need to grow and thrive.

Adjust the pH of the soil to the optimal range for your plant. Iron is most available to plants in slightly acidic soil with a pH between 6.0 and 6.5.

Add iron to the soil. Iron sulfate and chelated iron are two commonly used iron supplements. Follow the manufacturer's instructions for application rates.

Add well-rotted manure or compost: Adding well-rotted manure or compost can help prevent iron deficiency in plants. These organic materials can help improve soil structure and fertility, making it easier for plants to access the nutrients they need, including iron. It's important to use well-rotted materials, as fresh manure or compost can actually tie up nutrients in the soil and make them unavailable to plants. 

Water: Ensure the plant is not overwatered, as waterlogged soils can limit the plant's ability to absorb iron.

Phosphorus soil: Avoid planting in soils with high phosphorus levels, as this can limit iron availability to the plant.

Sprays: Consider foliar sprays of iron chelates or iron sulfate, which can quickly correct iron deficiency symptoms.

It's important to note that excessive amounts of iron can be toxic to plants, so be sure to follow application instructions carefully and only add iron to the soil when it is needed.

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lya Maximenko, Shutterstock

While every effort has been made to describe these plants accurately, please keep in mind that height, bloom time, and color may differ in various climates. The description of these plants has been written based on numerous outside resources.

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