Yellow Leaves On Plants – 10 Things You Need to Know

Sharing is caring!

Yellow leaves on plants are one of the most common plant problems faced by almost every gardener. Yellow leaves on plants indicate your plant is distressed and needs extra care.

It could be due to pests, diseases, nutrition, or even the medium in which the plant is growing.

 

 

Plants show their unhappiness by dropping yellow leaves on plants. Yellowing leaves make the plant look unattractive and might also indicate a fatal future problem which would otherwise affect the fruit or flower growth on the plant.

If you have ever faced the daunting thought of why are the leaves on my plant turning yellow?

We are here to help you. In this article, we have gathered all the possible causes and remedies for Yellow leaves on plants on plants to help you keep your plants happy and healthy.

 

 

 

MOISTURE STRESS

Moisture stress is the most common reason for yellow leaves on plants; either overwatering or under watering can cause the green foliage of the plants to turn yellow.

So if your plant is suffering from yellow leaves, look out for your watering habits.

Watering is the most crucial element for plant care, but each plant has different watering requirements. Know your plant needs and water accordingly to avoid moisture stress.

 

Underwatering:  yellow, dry and curling leaves

Examine the top 1-2 inch of the soil; if it’s dry and crumbly, then the plant is under-watered. When there is a lack of water, the plant will shed some leaves to conserve moisture.

There is a possibility that you might be watering only the top of the soil. Water the plant slowly so that the roots can absorb the water. 

If you think the soil is over draining, try adding a layer of mulch around the plant to retain the moisture.

 

Over-watering: yellow, drooping and dull lifeless leaves

Examine the top 1-2 inches of soil; if it feels very wet, you are overwatering the plant.

Overwatering can waterlog the soil, without oxygen roots start to die and the plant starts yellowing.

Reduce the amount of water or water less frequently. You can also improve the soil drainage by using sand or replant at a slightly raised location.

Make sure potted plant containers have holes at the bottom to allow the drainage of excess water. Keep in mind that in cold weather, the plant needs less water as the rate of evaporation is low.

The simple rule for watering is to examine the soil before watering and water only when necessary. If the soil feels damp, skip the watering.

 

LIGHT

If you are sure that you are watering the plant well, your plant might be starving for sunlight or scorching from excessive light. Not receiving enough light can also turn the leaves yellow.

Plants that get too little light start to yellow on the lower leaves, and eventually, the leaves start dropping.

A plant that is yellowing from a lack of light will typically yellow on the side that is away from the light source. 

Plants utilize sunlight to create chemical energy, but the lack of sunlight can limit the rate of photosynthesis.

In this case, the leaves look droopy and faded. For landscape plants, to check if your plant is receiving proper light, examine the lower leaves.

If the lower leaves are pale yellow, the plant is facing light deficiency. 

Reposition your plant in a new sunny location and see how it performs. Your plant might be located in a crowded area where. Trim the nearby plants to allow proper sunlight.

Different plants require different hours of direct sunlight for healthy growth. For your indoor plants in winter, you can get an artificial plant light to supply the light necessary for the plant.

While some plants are sun lovers and need direct sunlight, everyday others require low to medium light. The extra light will scorch such species. Read the plant label carefully to understand the lighting needs.

 

TEMPERATURE

If the whole plant is yellowing and the leaves have started dropping, this indicates that your plant is not happy with the temperature. It’s either too cold or too hot.

Most indoor plants are tropical; they prefer warm temperatures. If your indoor plant is located near an air-conditioner, it may cause cold drafts. Cold drafts make your plant chilly and waterlogged. 

Mist your indoor plants during cold drafts to increase humidity. During cold conditions, the chemical reactions are slowed down, which reduces chlorophyll production. As a result, the plant loses its green color. 

Indoor plants can suffer from inconsistent temperatures within the house.

Avoid placing the indoor plants near drafty windows or close to heating/ air-conditioning sources.  Temperature fluctuations or extreme temperatures can disturb the plants.

 

NUTRIENTS

If the plant is well-watered and receives proper sunlight, the next thing is to check for nutrient deficiencies. The nutrients requirements vary depending on species.

Leaf deformities with discolored or yellowing veins, tissue indicate your plant is suffering from nutrient deficiency.

Injured or weak root growth makes it difficult for the plant to absorb the nutrients. Either the nutrients in the soil are insufficient or unavailable due to high ph. You can also test the soil to check which nutrient is missing.

For plants, growing in containers, limited space is available for the roots to grow and store moisture. If your indoor plant has started showing yellow leaves despite all the plant care, consider repotting the plant to a bigger container or try fertilizers.

Most plants need essential nutrients in the soil for their growth; the yellow pattern on the leaves can help you decide which vital nutrients are missing.

Following are some of the common nutrient deficiencies that cause yellow leaves on plants:

Nitrogen: Older leaves on your plant are turning yellow, and the new leaves are very light green. Add organic compost or coffee grounds to the soil at the base of the plant or apply a balanced fertilizer.

Potassium deficiency: The edges, tips, and veins of the old leaves become yellow with brown spots.

Add citrus rinds or coverings to the base of the plants. You can also add compost enriched with fruit and vegetable waste or a potassium fertilizer.

Iron deficiency: When the leaves become yellow with small green veins and stunted growth. Check the pH of the soil and bring it below 7 by adding sulfur. Reduce the amount of phosphorus in the soil. 

Calcium deficiency: The leaves have yellow or brown spots surrounded by brown edges. For acidic soil, add use lime and for alkaline soil use gypsum.

Zinc deficiency: The leaves are discolored, and the tissue between veins is yellow while the veins are green. Spray the plant with kelp extract.

Magnesium deficiency: Yellowing of lower leaves between the veins. Add organic compost with magnesium, lime, or Epsom to the soil.

During growing season primary source of nutrients are fertilizers; use the fertilizers at the labeled rate to avoid under or over-fertilizing.

To overcome nutrient deficiencies, you can either use fertilizers or organic food for the plants. You can read more about soil nutrients and fertilizers in our extensive article.

 

DISEASES

Another reason for yellow or discolored leaves is disease or fungus. If your plant has blotchy leaves with yellow patches, deformed stems, and discolored flowers, it has a viral infection.

Some of the diseases are incurable and can spread to other nearby plants.

Therefore treat or dispose of the plant immediately. Don’t forget to wash and disinfect the tools before reusing them. 

Yellow leaves on plants may be due to any of the following diseases:

Leaf spot: Many annual and perennial flowering plants are susceptible to bacterial leaf spot. The spots are brown or black, with dark rings around the spots.

Plants infected with leaf spots will have yellow leaves, and the leaves may drop. Most leaf-bearing plants are susceptible to this disease.

The fungus of leaf spot can survive in plant debris and spread to other plants. Properly treat or dispose of the infected plant to control the spread of the disease.

Use a garden fungicide to treat the plant and change the pH balance to avoid the infections. You can also use a tablespoon or two of baking soda and a teaspoon of mineral oil in a spray bottle of water.

Black spot: It is an infectious fungal disease that resembles black splotches. It causes yellowing leaf, premature leaf drop, and there is a decline in the growth of the plant.

It occurs during moist and humid conditions and affects the new leaf tissues. Use a sulfur or copper fungicide to treat black spot and focus on the following:

• As black spot thrives in wet conditions, keep the leaves dry by ensuring good air circulation and water the plant at the base instead of top or leaves.
• Keep the soil well-drained to discourage the growth of fungal diseases.
• Using organic compost will provide microorganisms activity to fight diseases and plant problems.

Powdery mildew: It is the most common plant disease. It is a gray or white matter on the leaves that resembles dust or dirt.

It first appears on the lower leaves of the plant and can spread to the entire plant if left untreated.

The main symptoms are distorting of leaves, buds, tips, or fruits followed by yellowing of leaves or tissue death.

You can use a garden fungicide when you first see the symptoms of powdery mildew, apply again after 7 to 10 days to eliminate the disease.

Rust: There are more than 5000 species of rust that can infect plants. Fungal parasites cause rust, and it appears as brownish-yellow or bright orange spots on the leaves.

The spots contain a powdery substance known as spores, which will spread the disease to other plants via air or water.

The most common symptoms are the defoliation, reduced flower production, or dying branches. Immediately remove the infected parts of the plant and destroy them to control the spread.

To prevent rust, dust your plants with sulfur and maintain proper spacing to allow air circulation. You can also spray your plants with a rust fungicide. 

Mosaic virus: It is a viral disease affecting a wide variety of horticulture plants.  The main symptoms are yellow or white spots/ streaks on the plant foliage, yellowing veins, and stunted growth.

This virus lives on perennial weeds and can spread by garden pests such as aphids, leafhoppers, whiteflies.

You should immediately destroy the infected plants and sterilize the garden tools to prevent the spread of the virus throughout your garden.

You can read our in-depth article about the destructive and highly contagious Mosaic Virus here.

 

PESTS

If your plant has passed all the previous reasons, the culprit for yellow leaves on plants could be the sucking insects that feed on the plant sap.

If the plant’s health is declining and the leaves are crinkled, you should check your plant for pests.

For pest infections, you will notice other symptoms in addition to yellow leaves.

Such as tiny holes on the leaves indicate spider mites or pieces of leaf missing. You can control pest infections by using organic insecticides, horticulture, or neem oil.

Most pests thrive in dry conditions keep the humidity level high. Check your plants for the following pests:

Spider mites: They suck chlorophyll from leaf tissues and create yellow or white spots known as stipples. They thrive in hot and dry conditions.

Spider mites are difficult to see with the naked eye, but the main symptoms are webbings on the leaves and discoloration as well as yellow leaves on plants.

Inspect the top of the leaves for stippling and underside for webbing. You can use a horticulture oil or insecticidal soap to eliminate the mite eggs.

Keep the plant clean, cool; maintain proper watering, and fertilizing practice. Avoid over-fertilizing with nitrogen fertilizer as it helps in mite growth. 

Whiteflies: They infect several ornamental and vegetable plants. Whiteflies lay their eggs on new leaves. They feed on the leaves, which produce stippling of leaves, leading to yellow, dry, and distorted leaves.

Whiteflies secrete honeydew, which makes the leaves sticky with black mold. Heavy feeding by whiteflies can wilt and stunt the plant.

Spray an insecticidal soap on the underside of leaves and repeat the spraying if necessary.

Do not spray the plant in scorching weather. Horticulture oils are proven to be effective against all stages of this pest infection.

Aphids: They are the most common pests for both indoor and outdoor plants. Aphids are small yellow, red, or black colored sucking insects that feed on the sap of the plant.

If aphids have infested your plant, the growth stunts, the leaves will curl, wilt or become yellow.

Pinch and prune infected parts of the plant. You can get rid of aphids using natural and organic control methods.

Use a bug blaster to remove the pests from the plant by using a strong stream of water. Apply Diatomaceous earth for long term protection from aphids.

Read our aphid article for even more tips and tricks to identify and get rid of aphids.

Scale insects: These insects attach themselves to the branches, leaves even fruits of the host plants. The most common host is ornamental shrubs, houseplants, backyard trees, or greenhouse plants.

When scale insects heavily infect the plant, it suffers from weak growth and chlorotic (yellow) leaves.

If the infection is left untreated, the plant will eventually die.

Prune and dispose of the infected branches, twigs. Horticulture oils are the most effective choice against the larvae and even adult scale insects, which are protected by their armor coverings.

 

TRANSPLANT SHOCK

It refers to the stresses experienced by a recently transplanted plant or shrub. It occurs when the plant has not established an extensive root system in its new location.

The plant is disturbed because the roots cannot absorb enough water for plant growth.

Leaf scorching is the first symptom of this condition; leaves and the tissue start yellowing and dry out. The leading causes of this are a weak root system, improper planting techniques, and watering. 

The plants experiencing transplant shock are easily susceptible to diseases, insects, or weather. Such plants require extra care and watering to overcome this condition.

You can avoid transplant shock by hardening seedlings and gradually introducing them to the outdoor environment.

 

CHEMICALS

The wrong or excessive application of chemicals to the plants causes pesticide burns. The main symptoms of pesticide burn are leaf spots, yellowing leaf, or tip burn.

Avoid spraying the damaged or sensitive plants with pesticides or horticulture oils in very hot or humid weather.

Spray the plants in dry and cool conditions when the temperature is below 29 degrees Celsius. Always read the label and instructions carefully about the applications or precautions to avoid pesticide burns.

 

FERTILIZER BURN

Excessive fertilizing causes browning of leaf edges or leaf scorch. You might be using too much fertilizer to encourage growth, but this creates a toxic environment and burns the leaves.

The salts in the fertilizer extract the moisture from the root tissues leading to wilting, yellowing, and stunting. In hot weather, over-fertilizing can severely damage the roots of the plant.

Fertilizer burns can be avoided by using a slow-release fertilizer or adding 1-2 inches of compost. Look for plant food with the required nutrient and follow the recommended feeding rate to prevent fertilizer burn.

 

AGING

 

 

Yellow leaves on plants don’t always mean the plant is sick. If the plant is healthy and growing, but you notice some yellow leaves on the bottom of the plant, your plant is probably aging.

As plants get older, the bottom (most mature) leaves will turn yellow and fall off to encourage new growth. It is a natural process, and there is nothing to worry about.

The old leaves will die off, and new ones will come as the plant grows.

You can differentiate natural aging from other reasons by examining the rate at which the plant is yellowing.

If one or two leaves are yellowing at a slow and steady pace, your plant is experiencing the natural leaf shedding process. Aging is a healthy part of the plant life cycle.

 

FREQUENTLY ASKED QUESTIONS

 

Why are the leaves of my succulent turning yellow?

Succulents have thick and fleshy leaves to help store water. But overwatering succulents cause edema. In this condition, the leaf cells swell and break.

You will notice brown growth on the leaves and yellowing foliage. Watch out your watering habits during winter; only water if the top of the soil is dry.

You can also replant the succulent in a fast-draining soil mix.

 

How can I test the garden soil for nutrient deficiencies?

You can take soil samples from various areas in your garden to a local lab or gardening center for soil testing. The test will provide the pH level and nutrient deficiencies for soil.

Testing your garden soil will also help you measure the health and fertility of the soil.

The soil test data can help you fix the nutrient issues, choose the right fertilizers, and inform you about any soil problems specific to your geographic region.

 

How can winter dormancy cause yellow leaves on plants?

In the growing season, plants use the photosynthesis process to convert carbon dioxide, water, and other salts to carbohydrates and conserve energy.

Then in winter months, these are used by the plant roots to supply the nutrients for the plant. Removing the chlorophyll will cause the leaves to become yellow, orange, or red.

The plant is no longer growing; it focuses on survival by going dormant during winter.

Yellow foliage indicates plant problem; that is sometimes serious and sometimes temporary.

In most cases, you can fix the yellow leaves on plants by changing the plant care routine. It is essential to familiarize yourself with plant-specific needs for indoor and outdoor plants.

Any change in the color of leaves indicates nutrients or environmental problems. Remove the damaged leaves to help the plant direct its energy towards new healthy growth.

Properly treating your plant can help you regain the lush green foliage.

 

Conclusion

Yellow leaves on plants can stress plant owners out as it often indicates that something is wrong. The trick part is that it is not always sure what is wrong.

From over- to underwatering to plant pests there can be many reasons why leaves on plants turn yellow. Or it might just be old leaves and it can be completely natural. 

I hope with this extensive in-depth guide I provide you most if not all the reasons why leaves on plants turn yellow.

It is important to not freak out and look at the different reasons and rule them out one by one to find the cause.

There are reasons such as root rot that might cause leaves to yellow and be serious. There might be other reasons such as aging leaves and there is nothing you have to do about it.