Allium fistulosum Yellow Leaves - Causes & Fixes

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Nitrogen Deficiency

Green onions have a high demand for nitrogen to produce their characteristic green, succulent leaves; a lack of nitrogen causes the oldest leaves to turn pale yellow first.

Very Common

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How to confirm: Check if the yellowing started on the older, outer leaves and if the new growth appears significantly smaller or stunted.

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shopping_cart Recommended Products

1 Apply a nitrogen-rich liquid fertilizer to provide immediate nutrient uptake for the developing leaves.

FoxFarm Grow Big Liquid Plant Food 1 Quart

0.9 L • 1 pcs

$30

In Stock

2 Supplement the soil with an organic nitrogen source like blood meal to ensure a sustained release of nutrients.

Back to the Roots Organic Blood Meal

Organic Fertilizer

$10

In Stock

3 Monitor soil moisture levels using a moisture meter to ensure the nitrogen is being effectively transported to the roots.

GROWIT Soil Moisture Meter - Blue

Water Meters

$12

In Stock

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Overwatering and Root Hypoxia

Excessive moisture in the soil displaces oxygen, leading to root suffocation and preventing the plant from transporting nutrients effectively, resulting in yellowing foliage.

Very Common

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How to confirm: Press your finger into the soil near the base of the plant to see if it feels saturated or muddy.

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shopping_cart Recommended Products

1 Immediately stop watering and allow the soil to dry out significantly to restore oxygen to the root zone.

GROWIT Soil Moisture Meter SMM-V3

Water Meters

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2 Check the drainage of your container; if the soil remains saturated, repot the plant in a well-draining medium enriched with perlite to improve aeration.

3 Ensure the plant is in a pot with adequate drainage holes and use a saucer to catch excess water, but do not let the pot sit in standing water.

Bleuhome 10" Plant Saucer 6-Pack Black

Pot Saucers

$20

In Stock

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Allium Leaf Blight (Phytophthora)

This fungal-like pathogen causes water-soaked lesions that eventually turn yellow and can lead to the collapse of the hollow leaves in high-humidity environments.

Common

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How to confirm: Inspect the base of the leaves for dark, slimy lesions or signs of decay near the soil line.

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shopping_cart Recommended Products

1 Remove and destroy all heavily infected or yellowing leaves to prevent the pathogen from spreading through the plant population.

2 Apply an organic fungicide to control the spread of the blight and protect healthy tissue.

Bonide Captain Jack's Copper Fungicide 32 oz

0.9 L • 1 pcs • Organic

$12

In Stock

3 Improve air circulation and reduce humidity around the plants, and avoid overhead watering to keep the leaves dry.

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Temperature Stress (Cold Shock)

Extreme fluctuations in temperature or sudden exposure to frost can damage the cellular structure of Allium fistulosum, causing chlorophyll degradation and yellowing.

Common

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How to confirm: Determine if there has been a recent significant drop in nighttime temperatures or an unexpected frost event in your area.

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shopping_cart Recommended Products

1 Move the plant to a stable, sheltered environment to protect it from further temperature fluctuations and frost exposure.

2 Monitor soil temperature and moisture levels closely to ensure the roots are not experiencing additional thermal stress.

GROWIT Soil Moisture Meter - Blue

Water Meters

$12

In Stock

3 Apply a mild liquid fertilizer to help the plant recover and boost nutrient uptake once temperatures stabilize.