Probably about half a dozen times in my life as a gardener, I’ve gone outside to check on my corn plants only to discover that my corn plant leaves are turning yellow. Corn and peppers are my gardening nemeses, I had a really hard time getting their conditions right when I first started gardening. Yellowing corn leaves have a few different causes, which we’ll cover in this article. The good news is that most of them are fixable. The bad news is that, while recovering, your corn plants may fall a bit behind and not yield quite as much corn as they otherwise would.
Why Your Corn Plant Leaves Are Turning Yellow
There are 5 common reasons that corn plant leaves turn yellow, including nitrogen and potassium deficiencies, poor root development, dry soil, root rot, and damage from herbicide drift. Let’s dive into each one of these causes and how to fix them.
Nutrient deficiencies
Nitrogen deficiency is the most common nutrient deficiency that causes yellow corn leaves. The first leaves impacted by yellowing due to nitrogen deficiency will be lower on your plant. In younger plants, a lack of sufficient nitrogen will cause stunted growth that they never fully recover from. Yellowing will begin at the tips of your corn leaves and migrate inward to the leaf’s veins. You might expect yellowing corn leaves near the bottom of your corn plant to be a normal part of growth. In truth, you don’t want to see lower leaves of your corn plant fail to thrive until near the end of the growing season. If you suspect a nitrogen deficiency, you can use a nitrogen-heavy fertilizer, 46-0-0, to feed your corn plants.
A potassium deficiency will first present as yellowing tips and edges of your corn plant leaves, especially on lower leaves. Eventually, that yellowing will overtake much of the impacted leaf, eventually turning the leaves brown and killing them. Potassium helps your corn plant uptake water during dry conditions, so a potassium deficiency starves your plant of water between rainfall and irrigation use.
Poor root development
Poor root development from improper watering can turn corn leaves yellow because when the roots are not deep enough to absorb enough water, they are unable to transport the nutrients they need to the leaves. As a result, the leaves become deprived of the necessary nutrients and begin to turn yellow. This is a sign that the corn is not getting enough water, and it can lead to stunted growth, reduced yields, and even death if not addressed. If the root development is improved, by providing the corn with consistent and sufficient amounts of water, then the leaves should start to look greener and healthier. Watering thoroughly and deeply encourages your corn plants to grow deep roots.
Dry soil
Dry soil is a common cause of yellow corn leaves. When soil is dry, the roots of the corn plant are unable to absorb enough water to keep the leaves healthy. Without enough water, the leaves become yellow and weak. Lack of water is also a major cause of nutrient deficiencies in the plant, as the roots are unable to take up enough of the essential nutrients from the soil. Additionally, dry soil can lead to high levels of soil pH, which can cause the leaves to become yellow. With dry soil, the plant is unable to access the necessary nutrients and water to remain healthy, leading to yellow leaves.
Root rot
Root rot is a common problem that can cause yellow corn leaves. Root rot is caused by a variety of different fungi, such as Pythium and Phytophthora spp. These fungi infect the corn plant’s root system, attacking the roots, stalks and leaves. As the fungi spread, they consume the nutrients, water and oxygen needed for the plant to survive, leading to yellowing and wilting. In extreme cases, root rot can cause the plant to collapse and die. The damage to the roots makes it difficult for the plant to absorb essential nutrients, leading to yellow, stunted growth and leaves. Additionally, as the fungi spread, they can cause a decrease in the plant’s ability to take up water, which further weakens the plant and leads to the yellowing of the leaves.
Damage from herbicide drift
If you’re growing an organic garden that utilizes no herbicides for weed control, you might expect that herbicides aren’t the reason for yellowing corn leaves. But take stock of where you’re located. Are you situated near other conventional farms that might be spraying herbicides? If so, it’s possible that herbicide drift has caused the yellowing of your corn leaves.
Reasons for yellow spots on corn leaves
Anthracnose leaf blight is a fungal disease caused by the Colletotrichum graminicola fungus. It is typically spread during warm, wet periods in the growing season and can cause yellowing and wilting of corn leaves. Infected leaves may also have brown or black spots on them.
To fix anthracnose leaf blight, the most important thing is to practice preventative measures such as crop rotation and using resistant varieties of corn. In addition, fungicides can be used to treat the affected plants. It is also important to remove and destroy any affected plant material to prevent the spread of the disease.
Why are my corn seedlings turning yellow?
Corn seedlings turn yellow due to a lack of nutrients such as nitrogen or sulfur, or due to diseases or insect damage. Environmental conditions such as too much or too little water, extreme temperatures or a lack of sunlight can also cause corn seedlings to turn yellow. Ensure that your seedlings are growing in nutrient rich soil, are getting adequate water, and aren’t being attacked by posts.