Updated at: 30-05-2022 - By: Sienna Lewis

I just observed that some of my houseplants’ upper leaves had turned yellow. Upon more investigation, I discovered that this is a clear sign of iron deficiency. I decided to look at soil iron enrichment options.

So, what’s the best way to get iron into your garden soil? It’s possible to enrich the soil with chelated iron powder or blood meal. Add your own organic compost or fertilizer if it has enough iron. Spraying the leaves of the plant with chelated iron or iron sulfate in liquid form can also be used to boost iron levels.

It’s a good idea to double-check that your soil actually needs extra iron before you start adding supplements and fertilizers. To begin, let’s examine iron’s role in plants and the signs of an iron deficit. You’ll be able to identify if your plants are iron-deficient this way.

Then, we’ll discuss the reasons of iron shortage and how to remedy the situation in each scenario. Adding iron to your soil or plants is the final step in this discussion.

Why is Iron Important for Plants?

Plants use iron in a variety of ways. To begin with, iron is necessary for the photosynthesis process, which results in the formation of chlorophyll. Keep in mind that plants’ green color is due to the presence of chlorophyll.

Improvement iron deficiency of plants | Grow healthy plants - YouTube

Aside from its role in photosynthesis and respiration, iron is also crucial in the production of energy for plant growth.

Aside from that, iron aids in the transportation of nutrients like oxygen throughout the tissues of a plant.

In a nutshell, iron is essential to the health and growth of plants. Deficiency affects all of the processes listed above, thus it’s important to be tested. The iron deficit in a plant can be detected by looking at the leaves.

Symptoms of Iron Deficiency in Plants

When you know what to look for, you can spot an issue before it gets out of hand and take the necessary actions to fix it. Iron deficiency in plants manifests itself in a variety of ways, including the following symptoms.

Iron Chlorosis

Iron chlorosis is one of the most visible signs of iron deficiency in a plant. You’ll notice the plant’s top leaves turning yellow first, and then the lower leaves will follow suit.

There will still be some green in the veins of the leaves. Interveinal chlorosis is the term used to describe the look of yellow leaves with green veins.

Because iron is an immobile nutrient, it affects the plant’s younger leaves first. Thus, a plant’s tissues are unable to easily transport iron.

While newer leaves soon turn yellow because they lack the necessary amount of iron, older leaves retain their iron and remain green for some time.

Poor Growth

Poor growth is another symptom of an iron deficit in a plant. A plant like this may appear to be smaller than the rest of the ones in your garden. As a result, it won’t be able to grow as swiftly or as tall as before. Plant respiration and nutrient transport are hampered when an iron deficit is present.

Small Flowers or Lack of Fruit

Another possible effect of iron shortage is that a plant may grow tiny flowers and yield fewer fruit than healthy plants. A plant’s ability to synthesize and use sugar for energy or to develop blooms and fruit is affected by a shortage of iron.

Causes of Iron Deficiency in Plants

Once you’ve learned what iron deficiency looks like in plants, it’s time to figure out how it occurs. You may be surprised by some of the reasons!

High pH (Alkaline Soil)

Even though your soil contains sufficient of iron, your plants may suffer from an iron deficit if the pH is too high. I don’t understand how this could have happened.

There is an appropriate pH range for the soil for every nutrient that a plant need, including iron. During this time period, the nutrient is readily available to the plant’s roots, making it easy for the plant to absorb.

Even though the nutrient is present in the soil, the plant cannot absorb enough of it since it is unavailable outside of this range.

Most plants thrive in soil with a pH of 5.5 to 6.5, which is considered somewhat acidic. Acidic soil, in particular, has a high concentration of iron (pH below 7).

As the pH level climbs to 8 or above, iron in the soil becomes less accessible. Check out this chart from Research Gate to see how pH affects the availability of nutrients in a certain food.

Acid-loving plants including raspberries, blueberries, pears and azaleas are more likely to suffer from iron chlorosis because of their acidic soil preferences.

Prior to adding iron supplements or fertilizers, you should evaluate your soil pH. Your pH may be the issue, and if you add iron when you don’t need it, you run the risk of iron toxicity (more on this later).

pH testing kits are available at garden centers or online. Learn how to test your soil in my post on soil testing.

Sulfur can be used to increase the acidity of your soil. See my article on how to increase the acidity of your soil for additional details.

Must Reads: The one gardening mistake you can't afford to make - Los Angeles Times

Nutrient Imbalance

Despite the abundance of iron in the soil, your plants may still be suffering from iron shortage, even if the pH is in the right range.

Make sure to keep things in perspective when you’re gardening. Each nutrient must be present in the correct proportions in the soil, in addition to having enough of each one.

A plant’s ability to absorb another nutrient can be hindered if it receives an excess of one. A plant’s ability to absorb iron can be hindered by an excess of phosphorus, for example. Using a garden fertilizer with a high phosphorus level can lead to this.

N-P-K (percentage by weight of nitrogen, phosphorus, and potassium) can be found on a fertilizer packet if you’re not sure. Phosphorus is represented by the middle number on a fertilizer package; for further information, see my article on fertilizer package numbers. Find a fertilizer with a lower (or zero) phosphorus concentration if you’re concerned about excess phosphorus.

Iron uptake in plants can also be hindered by high calcium. In soils with high levels of lime, this can happen (lime is just another word for certain calcium compounds). Adding lime as a supplement to your garden is risky if your plants are iron deficient.

Poor Soil

If your soil is overly damp or compacted, iron uptake will be hindered. Even if you use plastic to keep weeds at bay, this could happen. When the soil temperature is too low, your plant may struggle to absorb iron.

There may be benefits to adding organic matter to clay-based soil, such as peat moss or your own composted leaves and grass clippings (banana peels, coffee grounds, etc.) Check out my article on how to build your own compost for additional information.

Extreme Conditions

Plants that are exposed to iron deficiency-causing extreme weather conditions are likewise at risk. The uptake of iron by plants might be hampered by excessive heat or sunlight.

Temperature, like pH, falls within a specific range. The plant will begin to suffer if it is outside of this range. In terms of both length and intensity, the same holds true for sunlight.

Insufficient Iron in Soil

There may be a problem with your soil’s iron content if none of the preceding parameters apply to your garden. There are a number of reasons why this might happen. Because there was never enough iron in the soil to begin with, this could be the cause.

The iron in your soil may have been depleted, which is another reason. The same iron-hungry crop can become a problem if you plant it year-after-year in the same spot. Crop rotation can help reduce some of the depletion (plant a crop in different parts of your garden each year).

You’ll want to know for sure if your soil is iron deficient and how bad the problem is. A soil test kit, which can be purchased at a garden center or online, is the best way to find out.

A soil test kit can also tell you about the levels of other nutrients in your soil, such as iron.

What Does Iron Do for Plants?

Understanding the role of iron in plants requires an understanding of chlorophyll, the pigment that makes your plants’ leaves and stems green. In addition, chlorophyll is critical to plants’ ability to take in sunlight, which provides them with the nutrients they need to grow.

Chlorophyll production is unable to take place if the soil lacks iron. Chlorosis will cause it to turn a yellowish hue. Your garden’s foliage will be a drab yellow color instead of green.

Even plants won’t be able to reach their potential. Oxygen cannot be transported via the plant’s system even if it receives all the sunlight and water it needs.

What Causes Iron Deficiency in Soil?

Plants just require a minimal amount of iron, which is abundant in soil. It’s likely that your soil lacks iron, but this isn’t the only explanation for your plants’ iron shortage.

Even though iron is present in the soil, your plants may not be able to use it. If your garden soil is alkaline, this could be a problem. This indicates that the pH level is high. To find out your soil pH, you can either buy a soil test kit or have a sample sent to your local extension agency.

Aside from that, some plants are more susceptible than others to iron chlorosis. What kinds of plants require the most iron? Those that do well in acidic environments, such as farms. In other words, if you have holly, azalea, or rhododendrons, pay attention to how they’re growing and how they seem.

Iron deficiency can be caused by poorly draining soil. When watering your garden, be careful not to overdo it. Similarly, soil that is both dry and compacted is undesirable. Finally, soils with high concentrations of clay and phosphorus will perform poorly.

A Quick Way To Boost Iron In Your Soil

An Irish gardener imparted a piece of folk wisdom to me. She buried a scrap iron at the foot of her struggling apple tree after a local woman advised her to. The tree flourished the following year.

Gardeners and farmers have a lot of stories and superstitions to share. There is no doubt that they are not based on solid scientific evidence, but they are typically passed down through generations.

Rust or iron oxide, an underappreciated plant micronutrient, can be added to the soil at the base of a seedling apple tree by an old piece of scrap iron. An iron deficit, or iron chlorosis, produces yellowing leaves and a general lack of energy in plants. Acidic soils, soils with extra copper, manganese, or phosphorus, and soils with a high concentration of these metals can all contribute to the problem.

Because iron is required for the synthesis of chlorophyll, it has an effect on a plant’s ability to utilize solar energy. Plants need iron to turn carbon dioxide into oxygen as part of their respiratory system. Plants can be iron-deficient even if the soil contains a lot of iron. The iron in red soils, for example, is usually in an insoluble state, making it difficult for plants to absorb.

A piece of scrap iron buried next to the apple tree may have been the older Irish lady’s way of ensuring that the apple tree was getting enough iron. An accurate diagnosis of iron deficiency can often be made without the need of a full soil test.

Adding iron to the soil is as simple as utilizing iron scraps, but employing sharp, rusted metal in the garden comes with its own set of dangers. Iron chelated in powdered or granular form is a popular addition to soil. Iron chlorosis can be prevented in part by addressing other soil imbalances, such as pH and the other nutrients discussed before.

Adding Iron to Soil Naturally

There are a lot of people that have to deal with the health of their garden, but not everyone wants to use chemical or synthetic solutions to do so. The following are some simple, all-natural methods for boosting soil iron levels.

Natural Foliar Spray

Natural foliar spray is a simple and effective solution to soil iron deficiency. The fertilizer is sprayed directly on the leaves instead of being applied to the soil in this manner. Think of it as an iron supplement for plants, not the soil.

Natural components are used in the 13Essentials foliar spray fertilizer, which is safe to use because it is completely free of synthetic chemicals. Foliar sprays are often used every 10 days or every two weeks, regardless of the brand.

Even though iron chlorosis-suffering plants will benefit immediately from this, soil amendment should not be abandoned.

Soil Amendment for Adding Iron to Lawn or Garden

This procedure is critical if the soil is to replenish its nutrients. Composted material can be applied to your soil once you’ve validated that your soil has a high pH. Pine needles, dried leaves and grass clipping are all examples of compostable material.

Adding organic matter to the soil can be a big aid, but it can take years for this to take effect. As a result, we continue to urge that gardeners look for solutions on the market that include organic iron for plants as a quick fix for iron chlorosis.

To sum it up, iron is a crucial component of your garden’s ecosystem. For more than just keeping your plants green, iron is an essential part of their nutrition. You should also be aware that there are both short-term and long-term natural treatments to iron shortage.

We really hope that this information about the importance of iron has been helpful to you. We’d love to hear from you if you have any questions concerning this topic.

Compost vs. Fertilizer, Explained - Gardening Channel

How to Add Iron to Garden Soil

If you’ve made it this far, you’re quite sure your soil is poor in iron. The following methods will help you increase the iron content of your soil.

Chelated Iron

Adding pure elemental iron to your garden may not be enough to correct a soil iron deficit, as you might expect. There must be a way for the iron to reach the plants.

Chelated iron, for example, is available in both powder and liquid forms. For a long-term solution, you can just sprinkle the powder into the soil. If a plant’s iron deficit is threatening its survival, another option is to spray the leaves with a liquid iron supplement.

Iron Sulfate

Plants can also get iron in the form of iron sulfate. The liquid version can be sprayed on the plant’s leaves. In addition, iron sulfate provides plants with sulfur, another essential ingredient.

Blood Meal

An ingredient in blood meal is the dried and powdered blood of livestock slaughtered for human consumption. Soil can be mixed with this iron powder, just like with chelated iron powder. Adding blood meal to the soil does provide some iron, but it also contains a lot of nitrogen.

So, be sure you don’t wind up with too much nitrogen in your body. The vegetative stage of plant growth consumes a large amount of nitrogen, making this a challenging task. Although it is possible, I recommend checking out my article on low-nitrogen fertilizers for more information.

Compost High in Iron

Leaves, food leftovers (not meat!), and grass clippings can be used to produce your own compost. Your finished compost should have plenty of iron for your plants if your leaves and grass are not iron deficient.

Fertilizer High in Iron

You may buy a fertilizer that contains more iron right off the shelf. Because they will contain other nutrients, fertilizers may pose a concern.

Remember that too much phosphorus or calcium can prevent plants from absorbing iron from the soil, as we discussed earlier. If you add iron, the plant will not be able to utilize it.

A Few Words About Excessive Iron

This much concern about iron deficiency makes it seem impossible to have too much iron in the soil. However, it is possible, especially if you do not look for other issues before adding iron (pH level or levels of other nutrients). Iron insufficiency and photosynthetic disruption are also possible side effects of high iron levels.


You now know whether or not your plants have an iron deficit, and if so, what might be causing it. To resolve the issue, it’s time to venture outside into the garden.

I’m glad you found it useful. Leave your questions in the comments section below.