Yellow Leaves on Tomato Plants: Why It Happens and How to Fix It

Yellow leaves on tomato plants are a common problem with tomatoes that usually signals an issue with the plant’s growing conditions.

In most cases, yellowing is caused by one of a few key issues: watering problems, nutrient deficiencies, pest damage, or disease. Because these problems can look very similar in the early stages, careful observation is often needed to identify the true cause.

The pattern of yellowing (where it starts and how it spreads) is often the fastest way to narrow down the problem and choose the right fix.

In this guide, you’ll learn the most common reasons tomato leaves turn yellow and how to diagnose and correct each one so your plants can recover and continue producing strong, healthy fruit.

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In this guide

Use the links below to jump directly to the section you need.

• Yellow leaves on new tomato plants
• Underwatering
• Overwatering
• Nutrient deficiencies
• Fertilizer burn
• Too much compost
• Soil pH problems
• Too much sunlight
• Herbicide damage
• Garden pests
• Fungal and viral diseases
• End of season yellowing
• Tomato leaf yellowing printable

Yellow leaves on new tomato plants

Yellowing on newly purchased or recently transplanted tomato plants is often related to early growth stress or container conditions.

What it looks like

• Yellowing usually starts on the lowest leaves.
• Upper growth remains green and healthy.
• The plant continues to produce new growth.

Why it happens

This is typically caused by one or more of the following:

• Limited nutrients in small nursery containers
• Plants being crowded during early growth
• Natural shedding of older lower leaves as the plant develops

Transplant shock

Even healthy plants can develop yellowing leaves shortly after being planted in the garden. This is known as transplant shock and is usually temporary.

As long as the plant continues producing new green growth, it is not typically a cause for concern.

How to manage it

• Avoid purchasing plants that are already heavily yellowed or declining, as they may be stressed or more prone to pests and disease.
• Remove yellowing lower leaves if they are not recovering, so the plant can focus energy on new growth.
• Ensure consistent watering after transplanting to reduce shock.

Pro tip: A few yellow lower leaves on older or fruiting plants can also occur naturally due to reduced light penetration and aging foliage. This is generally normal if the rest of the plant is healthy.

Underwatering tomatoes (a common cause of yellow leaves)

Underwatered tomato plants develop yellow leaves because dry soil prevents roots from absorbing the necessary nutrients for healthy growth.

What it looks like

• Leaves turn yellow and may feel dry or crispy
• Lower leaves are usually affected first
• Plants may wilt during the day, but improve after watering
• Soil feels dry several inches below the surface

Why it happens

• Water is needed to move nutrients from the soil into the plant
• Low moisture levels limit nutrient uptake
• This stress shows up as yellowing leaves

How to fix it

• Provide about 1 inch of water per week early in the season
• Increase to about 2 inches per week once plants begin fruiting
• Water deeply rather than lightly every day
• Water at the base of the plant to keep foliage dry
• Water early in the day to reduce evaporation and stress

Container-grown tomatoes need extra attention, since pots dry out much faster than garden soil.

If your soil is consistently wet rather than dry, overwatering may be the cause instead; see the section below.

Overwatering tomatoes (another major cause of yellow leaves)

Overwatering is a common cause of yellow leaves because waterlogged soil prevents oxygen from getting to the roots.

What it looks like

• Leaves turn yellow but feel soft or limp (not dry)
• Plants may wilt even though the soil is wet
• Lower leaves often go yellow first
• Growth may slow, and leaves can drop in severe cases
• Soil remains consistently soggy or slow to dry

Why it happens

• Excess water fills the air pockets in the soil, reducing oxygen around the roots
• Without oxygen, roots cannot absorb nutrients effectively
• This leads to stress and yellow leaves

If the soil feels dry and plants are wilting, underwatering is more likely the cause. See the section above.

Nutrient deficiencies (a common cause of yellow leaves on tomato plants)

Tomato plants are heavy feeders, and when nutrients run low, yellow leaves are often one of the first signs.

What it looks like

• Yellowing can appear on older or newer leaves, depending on the nutrient
• Veins may stay green in some cases
• Growth may slow, or fruit production may decrease

Why it happens

• Tomato plants can use available nutrients in the soil quickly
• Prevalent during active growth and fruiting stages
• Without replenishment, deficiencies develop

How to fix it

• Start with a soil test to identify the exact deficiency
• Apply the correct fertilizer based on the results
• Avoid guessing since adding the wrong nutrient can make the problem worse

Quick guide to common tomato nutrient deficiencies

• Nitrogen deficiency: older leaves turn evenly yellow; plants grow slowly
• Potassium deficiency: yellowing starts at leaf edges, then turns brown (“scorched” look)
• Magnesium deficiency: yellow leaves with green veins (interveinal chlorosis)
• Calcium deficiency: affects new growth; often linked to blossom end rot
• Iron deficiency: yellowing on new leaves with green veins

Because these symptoms can overlap, a soil test is the most reliable way to confirm the cause before treating.

Helpful tools for diagnosing and fixing yellow leaves

If you need to correct a nutritional deficiency problem, these tools can help:

• Epsom salt (magnesium) – useful for correcting magnesium deficiencies that cause yellow leaves with green veins.
  View product details
• Bone meal (calcium) – helps support healthy growth and prevent issues like blossom end rot.
  Purchase here
• Balanced tomato fertilizer – a good general option once you’ve identified what your plants need.
  Browse fertilizers

Tomato plant fertilizer burn (too much of a good thing)

Adding fertilizer can help your plants, but too much can damage roots and cause yellowing leaves on tomato plants.

What it looks like

• Yellowing leaves, often with brown or burnt edges
• Slowed or stunted growth
• White crust or salt buildup on the  soil surface (especially in container-grown tomatoes)

Why it happens

• Excess fertilizer causes salt buildup in the soil
• These salts damage the roots and interfere with water uptake

How to fix it

• Flush the soil with water to help remove excess salts
• Reduce or pause fertilizing
• Always follow label directions when applying fertilizer

For container plants, ensure excess water drains freely to prevent salt buildup.

Too much compost can cause tomato leaf yellowing

Adding compost improves soil health, but excessive amounts (especially manure-based or unfinished compost) can lead to problems similar to fertilizer burn.

What it looks like

• Stunted or slow plant growth
• Leaves turn yellow, sometimes with signs similar to fertilizer burn
• Container plants are more likely to be affected

Why it happens

• Large amounts of compost can create excess nutrient levels
• Manure-based or unfinished compost may contribute to salt buildup
• This can damage roots and interfere with water and nutrient uptake

How to fix it

• Water deeply to help flush excess nutrients from the soil
• Avoid adding more compost until the plant recovers
• In containers, consider replacing part of the soil if buildup is severe

For best results, mix compost into the soil in moderation rather than applying large amounts at once. If symptoms resemble fertilizer burn, review the section above.

Soil pH problems can cause yellowing leaves on tomato plants

Incorrect soil pH can lead to yellowing leaves, preventing tomato plants from absorbing essential nutrients, a condition known as chlorosis.

What it looks like

• High soil pH (alkaline > 7.0): Iron deficiency –  young, top leaves turn yellow while veins remain green
• Low soil pH (acidic < 6.0): Nutrient imbalance – older leaves may yellow as magnesium and other nutrients become less available

Why it happens

• Tomato plants grow best in slightly acidic soil with a pH between 6.2 and 6.8
• When soil pH is too high or too low, nutrients may be present in the soil but become unavailable to the plant (nutrient lockout)
• This results in yellowing leaves and reduced plant vigor

How to fix it

• Test your soil to determine the current soil pH level
• To lower pH (make soil more acidic), amend with materials such as aluminum sulfate or sulfur
• To raise pH (make soil less acidic), add garden lime (calcium carbonate)
• Make adjustments gradually and retest to avoid overcorrecting

Check out this post for more information on soil pH and other tomato plant problems that can lead to yellowing leaves.

Too much sunlight can cause yellow leaves on tomato plants

While tomato plants need 6–8 hours of sunlight daily, intense heat and direct sun can damage leaf tissue, leading to yellowing and sunscald.

What it looks like

• Upper leaves may turn pale yellow, then fade to white or develop blistered patches
• Leaf tissue can become dry or papery in severe cases
• Fruit may develop pale yellow or white spots (sunscald)

Why it happens

• Excessive heat and intense sunlight can damage exposed leaf tissue
• Plants that are not hardened off are especially vulnerable
• Water stress increases the risk of sun damage

How to fix it

• Harden off young plants gradually before exposing them to full sun
• Provide temporary shade during extreme heat (such as shade cloth)
• Keep soil moisture consistent during hot weather
• Remove only severely damaged leaves; healthy foliage helps protect the plant

Herbicides can cause tomato plant leaves to turn yellow and curl

Tomatoes are very sensitive to weed killers. Even small amounts of herbicide drift or contaminated compost can cause yellowing, curling, and distorted growth.

What it looks like

• Leaves may be yellow, twisted, or curled
• New growth is often most affected
• Stems may become thickened or brittle
• Growth becomes stunted
• Symptoms often appear 7–10 days after exposure

Why it happens

• Herbicides interfere with normal plant growth processes
• Some disrupt plant hormones, causing abnormal leaf and stem development
• This leads to stress, yellowing, and distorted growth
• Herbicide drift from nearby areas (even a neighbor’s yard) can affect plants without direct spraying

Common causes of herbicide damage

• Glyphosate (Roundup): Often causes yellowing and stunted new growth
• Dicamba and similar herbicides: Cause severe twisting and downward curling
• Contaminated materials: Herbicide-tainted compost, manure, or hay can affect plants through the soil

How to fix it

• If exposure was recent (such as spray drift), rinse plants with water as soon as possible
• Remove only severely damaged growth and allow the plant time to recover
• Monitor new growth over the next few weeks
• If new growth appears normal, the plant may recover
• If distortion continues, replacing the plant may be the best option

Garden pests (a common cause of yellow tomato leaves)

Pests damage tomato leaves by feeding on plant tissue and sap, which can lead to yellowing and weakened growth.

What it looks like

• Yellowing leaves with speckling, spots, or holes
• Fine webbing, sticky residue, or visible insects
• Leaves may curl, dry out, or drop prematurely

Why it happens

• Pests feed on plant sap or foliage, damaging leaf tissue
• This disrupts photosynthesis and nutrient flow
• Warm, dry conditions often increase pest activity

How to fix it

• Inspect plants regularly, especially under leaves
• Remove heavily infested foliage
• Use appropriate treatments based on the pest
• Encourage beneficial insects and maintain garden hygiene

Common garden pests that cause tomato leaf yellowing

• Spider mites: Fine webbing and stippled yellow leaves. Wash plants with water or treat with insecticidal soap.
• Thrips: They cause silvery, speckled yellowing. Insecticidal soaps are effective.
• Potato aphids: Leaves turn yellow and brown from the top down. Neem oil works well.
• Flea beetles: Make tiny holes in leaves, and leaves turn yellow. Companion planting (like chrysanthemums) can help deter them.
• Nematodes: They cause root damage, stunted growth, and yellowing leaves. Crop rotation helps prevent infestations.

Fungal and viral diseases (a more serious cause of yellow tomato leaves)

Some of the most difficult causes of yellowing leaves are fungal and viral diseases, which spread rapidly and can impact the entire plant.

What it looks like

• Yellowing often appears alongside spots, lesions, or mottling
• Leaves may curl, wilt, or develop dark patches
• Yellowing may spread unevenly across the plant

Why it happens

• Fungal spores thrive in warm, humid conditions
• Insects such as whiteflies often spread viruses
• Soil-borne pathogens can infect plants through the roots

How to fix it

• Remove and dispose of affected leaves promptly
• Avoid overhead watering to reduce moisture on foliage
• Improve spacing and airflow between plants
• Rotate crops each season to prevent soil-borne diseases
• In severe cases, remove the entire plant to prevent spread

Common tomato diseases that cause yellow leaves

• Early blight: Yellowing with small dark spots that enlarge over time.
• Late blight: Affects upper leaves and can spread rapidly in cool, wet conditions.
• Fusarium wilt: Yellowing often appears on one side of the plant, and the disease causes stunted growth.
• Verticillium wilt: Older leaves yellow first, usually later in the season.
• Tomato mosaic virus: Causes mottled yellowing and leaf distortion.
• Tomato leaf curl virus: Spread by whiteflies; leads to yellowing, curling, and stunted growth.

If you are unsure which disease is affecting your plant, your local extension service can help with an accurate diagnosis.

Yellowing leaves at the end of the season

One of the most common causes of yellow leaves late in the season isn’t a problem at all. It’s simply the natural life cycle of the plant.

What it looks like

• Leaves and young stems turn yellow, then brown or black
• Stems become limp and watery, then dry and brittle
• Plants may look scorched or “burnt.”
• Damage is often most noticeable on tender upper growth

Why it happens

• As the growing season ends, tomato plants shift energy into ripening fruit instead of maintaining foliage
• Cool nights and early frost can accelerate yellowing and leaf damage
• This is a normal part of the plant’s life cycle

How to fix it

• Harvest mature fruit and bring green tomatoes indoors to ripen
• If frost damage is light, prune affected leaves
• After a hard frost, remove the plant and add it to the compost pile if disease-free
• Dispose of unhealthy plants to prevent overwintering pests and diseases

Get the tomato leaf yellowing printable

This printable shows the causes of yellow leaves on tomato plants and ways to fix them.

You can print the tomato leaf yellowing printable as high-resolution JPGs or PDFs by using the links below:

• Get the high-resolution tomato leaf yellowing printable (JPG)↗
• Get the PDF tomato leaf yellowing printable (PDF)↗

Printing instructions:

• Select portrait orientation and “fit to page” on your printer settings for a full-page printout.
• You can also print out the chart from the project card at the bottom of this page. Scroll down to the card and press “print.

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Admin note: This article about yellow leaves on tomato plants first appeared on the blog in June 2022. This post has been updated with more info, a free printable, and a slideshow video about the causes of tomato leaf yellowing.

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