Iron Chlorosis: What It is & How to Spot It Early

Reading time: 5 minutes

Like humans, plants and trees need iron to survive. This nutrient is essential for long-lasting trees and shrubs, which means you don’t want your tree to go without for too long. Regular tree care is essential when you notice your trees are starting to yellow.

When plants experience chlorosis, it means you can see visible signs of yellowing in the leaves. The term is used for several nutrient deficiencies in plants, so it’s important to remember. But if you’re wondering about iron chlorosis specifically, you’re in the right place.

Read on to learn about iron chlorosis, how to spot it, and what expert arborists do to treat this dangerous condition.

Leaf with iron chlorosis
Photo credits Utah State University

What is Iron Chlorosis?

As mentioned above, chlorosis is a term for yellowing in plants. When you spot yellowing on your trees, it could be because the tree lacks a nutrient. In the case of iron chlorosis specifically, your tree is experiencing a lack of iron.


The yellowing of leaves due to iron chlorosis happens when a plant can’t uptake iron to make the pigment chlorophyll. It tends to occur in soils high in lime or heavy clay, so while iron is a prevalent nutrient in soil, these soil types make absorption a lot more difficult. A high soil pH, excess moisture, or low soil temperatures can also cause the deficiency. You may also find this issue in trees that experience compacted soil and poor drainage.

What Plants Are Affected by Iron Chlorosis?

There are a number of tree and shrub species that are susceptible to iron deficiency. Plants that are native to areas with high lime or clay soils aren’t generally as likely to face this condition, but you are likely to find it in species like:

  • Freeman Maple
  • Silver Maple
  • Eastern White Pine
  • Azalea
  • Rhododendron

It’s also been noted in raspberry and blueberry plants. Because this condition can reoccur, you’ll even see many places recommend stopping planting some varieties, including both species mentioned above, some cranberry varieties, and other species, if plants continue to be affected by this deficiency.

Checking for Iron Chlorosis

Many tree conditions begin with the yellowing of leaves. This makes it more challenging to name iron chlorosis when it affects your trees. Many professionals will test for a litany of diseases, including a soil test to check the pH.

If it’s determined that the soil is high in alkalinity, iron chlorosis likely is what’s causing the yellowing. You can still expect visual signs from any tree when it experiences chlorosis.


You’ll likely notice the yellowing of your plant’s leaves first when your trees are battling an iron deficiency. Accompanying this yellowing is often a combination or network of darker green veins visible on the leaves. When the case is severe enough, the entire leaf will turn yellow or white and may brown or burn on the edges.

Additionally, you may only notice one or a few tree branches affected. Severe cases can impact the entirety of a tree, and you’re likely to find that one tree in your yard is affected while another of the same species is entirely fine.

Long Term Issues

The issues associated with iron chlorosis can be severe, resulting in tree death if the tree goes untreated. With property treatment, many trees can make a full recovery. The speed at which they can recover will depend on the species of tree. For example, oak trees can recover much faster than maples, with oak trees sometimes bouncing back within a season, while maples may take five years or more to recover.

Other long-term chlorosis issues include the death of branches, dropping leaves, and eventual tree death if left untreated.

Treating Your Trees: Best Practices

Iron chlorosis is challenging to treat and may become expensive to deal with. However, professional arborists use three primary methods to treat this nutrient deficiency.

Treat the Soil

The most effective way to treat chlorosis is by treating the soil around affected trees and shrubs. While there’s no right way to treat this issue, experts use a few techniques to make the soil more hospitable for the affected plants.

Adjust pH

Several steps go into adjusting your soil’s pH if a high pH is causing the issue. One of the first things you’ll need to do is test the soil and determine the extent of the problem. From there, you can commit to soil treatments that adjust the pH of your soil, like elemental sulphur or adding peat moss to the soil.

Iron Chelates

Chelated iron is an additive placed directly into the soil to assist with iron uptake through the root system. This enables the tree to get iron more quickly. Several types of chelates can be used, and most programs apply several treatments over the course of 3 years to ensure long-term results.

Add Micronutrients

While iron chlorosis occurs due to a lack of iron, other micronutrients can contribute to chlorosis, so adding soil amendments like micronutrients is a helpful way to repair damage from the initial issue.

Foliar Sprays

Using foliar sprays is a common tactic for younger plants and faster results. You’ll likely see results after 10 days on existing leaves, but new growth will still come in more yellow. Often, these treatments aren’t permanent and will require successive treatments.

Stem Treatments

An additional type of treatment is done at the trunk or stem of a tree or plant. This kind of treatment does require drilling into the trunk, often at the flare roots near the soil line, so that injections can be placed. This type of treatment should not be done more than once per year.

Get Your Trees Back on Track with Green Drop Certified Arborists

When you notice yellowing on your leaves, it’s no time to rest on your laurels. Don’t let your trees suffer through iron chlorosis without treatment. Instead, reach out to certified arborists to get your trees back on track.

The Green Drop arborists understand the best ways to help your trees look their best and treat diseases or nutrient deficiencies with our proven methods.

Contact us today for a free estimate on your customized tree care plan.

Schedule Your Free Tree Care Assessment