Should I remove yellow leaves from my tomato plant?

Yes, in most cases. Removing yellowing lower leaves improves airflow at the base of the plant, reduces the chance of soil-borne disease splashing up, and lets the plant redirect energy to healthy growth and fruit. This is especially worthwhile for the oldest bottom leaves, which naturally yellow as the plant matures. Use clean pruners and remove leaves that are more than half yellow or clearly diseased. Do not strip the plant bare, though — the leaves still power photosynthesis and shade the fruit from sunscald. Take a few at a time, and always diagnose why the yellowing is happening so you also address the underlying cause.

Why are the bottom leaves of my tomato turning yellow?

Yellowing that starts at the bottom of the plant has three common causes: natural aging, a nitrogen shortage, or overwatering. As tomatoes mature they let their oldest lower leaves yellow and die while pouring energy into fruit, which is normal. A nitrogen shortage also hits the lower leaves first, since the plant moves nitrogen up to new growth, and shows as uniform pale-yellow foliage. Overwatering yellows the lower leaves too, but comes with soggy soil. Early blight adds dark spots with concentric rings on those lower leaves. Check the soil moisture and look for spots to tell these apart.

Can too much water turn tomato leaves yellow?

Yes. Overwatering is a very common cause of yellow tomato leaves. When the soil stays waterlogged, the roots are deprived of oxygen and cannot take up nutrients, so the foliage yellows, usually starting low on the plant, even though water is abundant. Poor drainage, heavy clay soil, and frequent shallow watering all contribute. The fix is to water deeply but less often, letting the top inch or two of soil dry between waterings, and to improve drainage where water pools. Tomatoes want consistent moisture, but not constant sogginess. Mulching keeps soil moisture even and reduces the swings that stress the plant.

What deficiency causes yellow tomato leaves?

The pattern tells you which nutrient. Uniform pale-yellow older leaves point to nitrogen, the most common shortage, corrected with a balanced or nitrogen-forward feed. Yellowing between the veins while the veins stay green, on older leaves, points to magnesium, fixed with an Epsom-salt foliar spray at about one tablespoon per gallon. Yellowing between the veins on the newest top leaves points to iron, usually caused by waterlogged or alkaline soil rather than a true lack. Overall yellowing with older leaves affected first can also be potassium or sulfur. Feed to the specific pattern rather than guessing, and correct any drainage issue that may be blocking nutrient uptake.

Is yellowing tomato leaves a sign of disease?

It can be. Early blight causes yellowing lower leaves with dark brown spots ringed by concentric circles, spreading upward. Septoria leaf spot yellows leaves dotted with small dark-bordered spots. Fusarium and verticillium wilt cause yellowing and wilting, often on one side of the plant, with brown streaking inside the stem, and they are fatal soil diseases. Yellow leaf curl and mosaic viruses yellow and distort the leaves. So while much yellowing is nutritional or water-related, yellowing that comes with spots, one-sided wilting, or mottled distortion signals disease. Inspect for spots and slit a stem to check for internal browning before concluding it is a nutrient problem.

Why Are My Tomato Plants Turning Yellow? Causes & Fixes

Written & researched by Elena Marsh Gardening & Landscaping Editor

Updated June 2026

Low-angle view of a person harvesting ripe tomatoes into a basket in a backyard vegetable garden, in soft early-morning light

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Tomato plants turn yellow from several causes: a nitrogen or magnesium shortage, overwatering and poor drainage, diseases like early blight and fusarium wilt, sap-sucking pests, and the natural aging of the lowest leaves. The fastest way to diagnose it is to note which leaves are yellowing and in what pattern — old bottom leaves yellowing is often normal or a nitrogen sign, yellow-between-green-veins points to magnesium, and yellowing with dark spots or one-sided wilting means disease. Fix it by feeding to the deficiency, watering deeply but less often, and removing diseased leaves.

We do not test or physically handle the plants and products we cover; our guidance draws on horticultural extension research and the aggregated experience in thousands of owner reviews, as explained in how we rank.

Read the yellowing tomato pattern first

Which leaves yellow, where, and what accompanies it point straight to the cause. Start here before feeding or spraying.

What you see	Pattern	Likely cause
Oldest lower leaves yellow and die	A few leaves, rest of plant healthy	Natural aging (normal)
Uniform pale yellow, older leaves first	Whole leaf, spreads slowly upward	Nitrogen shortage
Yellow between green veins, older leaves	Veins stay green	Magnesium shortage
Yellowing lower leaves, soggy soil	Slow, from the base up	Overwatering / root rot
Yellow leaves with dark concentric-ring spots	Starts low, spreads upward	Early blight
Yellowing and wilting on one side, stem streaked brown	Progressive, does not recover	Fusarium or verticillium wilt

Low-angle view of a person harvesting ripe tomatoes into a basket in a backyard vegetable garden, in bright midday sun

Natural aging (rule this out first)

Check first whether only the oldest, lowest leaves are yellowing while the rest of the plant is green and vigorous. As tomatoes mature and put their energy into fruiting, they routinely shed their oldest bottom leaves, which yellow and die — normal senescence that needs no more than removing the spent leaves to improve airflow at the base. It becomes a concern when yellowing climbs into the upper canopy, appears in a distinctive vein pattern, or comes with spots or wilting. So the first diagnostic question is always which leaves are affected. A few aging bottom leaves on an otherwise healthy, fruiting plant is not a problem, while widespread or upward-spreading yellowing tells you to look deeper.

Nitrogen and magnesium shortages that yellow tomatoes

Tomatoes are heavy feeders and nutrient shortages commonly show as yellowing, with the pattern revealing the culprit. A nitrogen shortage produces uniform pale-yellow leaves beginning with the older, lower foliage, because the plant relocates nitrogen to new growth. Correct it with a balanced fertilizer or a nitrogen-forward feed at the label rate — but do not overdo it, since excess nitrogen drives leafy growth at the expense of fruit. A magnesium shortage, very common in tomatoes, yellows the tissue between the veins while the veins stay green, again on older leaves first; a foliar spray of Epsom salt at about one tablespoon per gallon of water corrects it quickly. Yellowing between the veins on the newest top leaves instead points to iron, usually a symptom of waterlogged or alkaline soil rather than a true lack, so fix drainage first.

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Overwatering that turns tomato leaves yellow

Overwatering is one of the most common and most misdiagnosed causes of yellow tomato leaves. Waterlogged soil forces oxygen out of the root zone, and roots starved of oxygen cannot take up nutrients, so the leaves yellow — typically the lower ones first — despite plentiful water. Heavy clay, poor drainage, and frequent shallow watering all contribute, and chronic sogginess leads to root rot. Water deeply but less often, letting the top inch or two of soil dry between waterings, and improve drainage where water pools. Tomatoes want consistent, even moisture, not constant saturation. A 2 to 3 inch mulch layer holds moisture steady and prevents the wide wet-dry swings that stress the plant and also cause blossom-end rot and fruit cracking.

Early blight and leaf spot

Fungal leaf diseases are a leading cause of yellowing that comes with spots. Early blight starts on the lower leaves as dark brown spots with concentric rings — a target or bullseye pattern — surrounded by yellowing tissue, and it climbs the plant over time, eventually defoliating it. Septoria leaf spot yellows leaves peppered with many small, dark-bordered spots. Both spread from soil splash and thrive in warm, wet, humid conditions. Manage them by removing affected lower leaves promptly, mulching to stop soil splashing onto the foliage, watering at the base rather than overhead, spacing and staking plants for airflow, and rotating where you plant tomatoes each year. Copper or other fungicides can slow the spread, but sanitation and airflow are the foundation. Remove and destroy badly infected leaves — do not compost them.

Overhead view of a person harvesting ripe tomatoes into a basket in a backyard vegetable garden, in warm late-afternoon light

Fusarium and verticillium wilt

These soil-borne fungal diseases are the serious, unrecoverable causes of tomato yellowing. Fusarium and verticillium wilt cause yellowing and wilting that frequently begins on one side of the plant or one branch, progressing until the plant declines, and slitting the lower stem lengthwise reveals brown streaking in the vascular tissue. The fungus blocks the plant's water-conducting system, which is why watering does not help. There is no cure. Remove and destroy affected plants — do not compost them — and because the fungus persists in the soil for years, rotate crops and grow resistant varieties. Look for the letters V and F after a tomato variety name, which indicate bred-in resistance to verticillium and fusarium; choosing resistant varieties is the most reliable defense in gardens where these diseases have appeared.

Pests

Sap-sucking pests yellow tomato foliage as they feed. Aphids cluster on new growth and undersides, whiteflies rise in a cloud when disturbed, and both suck sap, yellow the leaves, leave sticky honeydew, and spread viruses such as yellow leaf curl. Spider mites stipple leaves with fine yellow speckling and spin webbing on the undersides, worsening in hot, dry weather. Check the leaf undersides with a hand lens. Knock pests off with a firm spray of water, treat the undersides with insecticidal soap or neem, and repeat every few days until controlled. Because these insects also transmit yellowing viruses, keeping their numbers down protects the plant on two fronts. Encourage ladybugs and lacewings, and isolate heavily infested plants.

Preventing yellow tomato leaves: a checklist

Judge by which leaves yellow — a few old bottom leaves is normal; upward-spreading yellowing needs action.
Feed to the pattern — nitrogen for uniform pale leaves, Epsom-salt magnesium for yellow-between-green-veins.
Water deeply but let soil dry — soggy soil yellows leaves by starving roots of oxygen.
Mulch and water at the base — stops soil splash that spreads early blight and septoria.
Grow VF-resistant varieties — the best defense against fusarium and verticillium wilt.
Control aphids and whiteflies — they yellow leaves directly and spread yellowing viruses.

Related: why are my tomato plant leaves curling and why are my squash plants turning yellow, plus the Seeds & Vegetable Growing hub and how we rank.

Why Are My Tomato Plants Turning Yellow?