Is the deficiency on old leaves or new leaves?
How a nutrient moves inside the plant is the first filter for a leaf deficiency.[2][2] Tier 1 · Primaryuniversity_extensionUniversity of Arizona Cooperative ExtensionView source ↗ Verified 2026-05-02 Mobile nutrients (nitrogen, phosphorus, potassium and magnesium) can be pulled out of old leaves and sent to new growth when supply runs short.[2][2] Tier 1 · Primaryuniversity_extensionUniversity of Arizona Cooperative ExtensionView source ↗ Verified 2026-05-02 That is why a mobile nutrient deficiency shows up on the old lower leaves first.[6][6] Tier 1 · Primaryuniversity_extensionUniversity of DelawareView source ↗ Verified 2026-04-11 Immobile nutrients like calcium, iron, manganese and sulfur stay put once they are deposited in a leaf.[2][2] Tier 1 · Primaryuniversity_extensionUniversity of Arizona Cooperative ExtensionView source ↗ Verified 2026-05-02 An immobile nutrient deficiency shows up on the new upper growth instead.[3][3] Tier 1 · Primaryuniversity_extensionUniversity of HawaiiView source ↗ Verified 2026-04-11
The plant puts its growing tissue ahead of its oldest leaves.[6][6] Tier 1 · Primaryuniversity_extensionUniversity of DelawareView source ↗ Verified 2026-04-11 When a mobile nutrient runs short the plant pulls it from the older leaves and sends it to new growth, so the old leaves are sacrificed first.[6][6] Tier 1 · Primaryuniversity_extensionUniversity of DelawareView source ↗ Verified 2026-04-11 An immobile nutrient cannot make that trip once it is deposited, so the new growth goes without when supply is short.[2][2] Tier 1 · Primaryuniversity_extensionUniversity of Arizona Cooperative ExtensionView source ↗ Verified 2026-05-02 Checking whether the damaged leaves are old or new is the first step in narrowing down which nutrient is short.[3][3] Tier 1 · Primaryuniversity_extensionUniversity of HawaiiView source ↗ Verified 2026-04-11
N, P, Ca, Mg, S side by side
Nutrient deficiency symptoms usually spread symmetrically across the plant, while damage from insects or disease is patchy and one-sided.[6][6] Tier 1 · Primaryuniversity_extensionUniversity of DelawareView source ↗ Verified 2026-04-11
| Nutrient | Starts on | Look |
|---|---|---|
| Nitrogen[2][2] Tier 1 · Primaryuniversity_extensionUniversity of Arizona Cooperative ExtensionView source ↗ Verified 2026-05-02 | Old, lower leaves | Uniform pale yellow across the whole leaf, veins included |
| Phosphorus[3][3] Tier 1 · Primaryuniversity_extensionUniversity of HawaiiView source ↗ Verified 2026-04-11 | Old, lower leaves | Dark green shifting to purple, growth stunted |
| Calcium[2][2] Tier 1 · Primaryuniversity_extensionUniversity of Arizona Cooperative ExtensionView source ↗ Verified 2026-05-02 | New, upper growth | Distorted or curled young leaves, tip burn, blossom end rot in fruit |
| Magnesium[3][3] Tier 1 · Primaryuniversity_extensionUniversity of HawaiiView source ↗ Verified 2026-04-11 | Old, lower leaves | Interveinal yellowing, veins stay green |
| Sulfur[2][2] Tier 1 · Primaryuniversity_extensionUniversity of Arizona Cooperative ExtensionView source ↗ Verified 2026-05-02 | New, upper growth | Yellowing, easily mistaken for nitrogen |
How does nitrogen deficiency progress?
Nitrogen deficiency starts on the old lower leaves because nitrogen is mobile within the plant.[2][2] Tier 1 · Primaryuniversity_extensionUniversity of Arizona Cooperative ExtensionView source ↗ Verified 2026-05-02 The affected leaves go pale green and then yellow evenly across the whole leaf, veins included.[2][2] Tier 1 · Primaryuniversity_extensionUniversity of Arizona Cooperative ExtensionView source ↗ Verified 2026-05-02 The yellowing moves up the plant from the bottom as it progresses.[2][2] Tier 1 · Primaryuniversity_extensionUniversity of Arizona Cooperative ExtensionView source ↗ Verified 2026-05-02 Growth is stunted.[2][2] Tier 1 · Primaryuniversity_extensionUniversity of Arizona Cooperative ExtensionView source ↗ Verified 2026-05-02 In advanced deficiency the oldest leaves die off and the stems turn brown.[6][6] Tier 1 · Primaryuniversity_extensionUniversity of DelawareView source ↗ Verified 2026-04-11
Common causes are under-feeding, pH lockout, nitrate leaching, and a cold root zone.[4][4] Tier 1 · Primaryuniversity_extensionNC State UniversityView source ↗ Verified 2026-04-11 Excessive nitrate leaching, since nitrate moves in soil water, also contributes to the same deficiency.[4][4] Tier 1 · Primaryuniversity_extensionNC State UniversityView source ↗ Verified 2026-04-11 Overwatering can look similar but it droops the plant and hits all the leaves, so rule it out before blaming nitrogen.[1][1] Tier 1 · Primaryuniversity_extensionWest Virginia University ExtensionView source ↗ Verified 2026-05-02
How does phosphorus deficiency progress?
Phosphorus deficiency also starts on the old lower leaves because phosphorus is a mobile nutrient.[3][3] Tier 1 · Primaryuniversity_extensionUniversity of HawaiiView source ↗ Verified 2026-04-11 Affected leaves go a dull green with purple tints.[1][1] Tier 1 · Primaryuniversity_extensionWest Virginia University ExtensionView source ↗ Verified 2026-05-02 Growth is stunted.[1][1] Tier 1 · Primaryuniversity_extensionWest Virginia University ExtensionView source ↗ Verified 2026-05-02 Old leaves scorch at edges and wither early.[3][3] Tier 1 · Primaryuniversity_extensionUniversity of HawaiiView source ↗ Verified 2026-04-11 In organic growing media, causes include too little amendment, a pH that locks phosphorus up, or too little microbial activity.[1][1] Tier 1 · Primaryuniversity_extensionWest Virginia University ExtensionView source ↗ Verified 2026-05-02 Phosphorus deficiency shows on old leaves first.[7][7] Tier 1 · Primaryuniversity_extensionUtah State UniversityView source ↗ Verified 2026-04-11
How does calcium deficiency progress?
Calcium is immobile in the plant: once deposited in plant tissue it cannot be moved to younger tissue.[2][2] Tier 1 · Primaryuniversity_extensionUniversity of Arizona Cooperative ExtensionView source ↗ Verified 2026-05-02 So the deficiency shows up on the newest growth first and not on the old leaves.[2][2] Tier 1 · Primaryuniversity_extensionUniversity of Arizona Cooperative ExtensionView source ↗ Verified 2026-05-02 New leaves come in distorted, curled or cupped, and the leaf margins develop white spots and brown, dying edges.[2][2] Tier 1 · Primaryuniversity_extensionUniversity of Arizona Cooperative ExtensionView source ↗ Verified 2026-05-02 Growth at the growing points of both shoots and roots is held back.[2][2] Tier 1 · Primaryuniversity_extensionUniversity of Arizona Cooperative ExtensionView source ↗ Verified 2026-05-02
Blossom end rot is a calcium transport disorder.[4][4] Tier 1 · Primaryuniversity_extensionNC State UniversityView source ↗ Verified 2026-04-11 Blossom end rot is primarily a water management issue where soil calcium is adequate, because calcium moves through the plant in the water stream.[8][8] Tier 1 · Primaryuniversity_extensionUniversity of Florida IFASView source ↗ The same growing-point damage goes by crop-specific names: brown heart in escarole, blackheart in celery and tip burn in cauliflower and cabbage.[5][5] Tier 1 · Primaryuniversity_extensionUniversity of Florida IFASView source ↗ Verified 2026-04-11
How does magnesium deficiency progress?
Magnesium deficiency shows up on the old lower leaves first because magnesium is a mobile nutrient like nitrogen and phosphorus.[6][6] Tier 1 · Primaryuniversity_extensionUniversity of DelawareView source ↗ Verified 2026-04-11 The signature symptom is interveinal chlorosis: the tissue between the veins turns yellow while the veins stay green, which gives the leaf a striped or netted look.[3][3] Tier 1 · Primaryuniversity_extensionUniversity of HawaiiView source ↗ Verified 2026-04-11 Magnesium sits at the center of the chlorophyll molecule, which the plant needs for photosynthesis.[3][3] Tier 1 · Primaryuniversity_extensionUniversity of HawaiiView source ↗ Verified 2026-04-11 High levels of potassium, sodium or calcium can bring on the same deficiency through nutrient antagonism, and strongly acidic soil also cuts down how much magnesium is available.[3][3] Tier 1 · Primaryuniversity_extensionUniversity of HawaiiView source ↗ Verified 2026-04-11
How does sulfur deficiency progress, and why is it confused with nitrogen?
Sulfur deficiency shows as general yellowing on new upper growth first because sulfur has little to no mobility in the plant.[3][3] Tier 1 · Primaryuniversity_extensionUniversity of HawaiiView source ↗ Verified 2026-04-11 That yellowing is easy to confuse with iron or manganese deficiency, and it can look like nitrogen deficiency too.[1][1] Tier 1 · Primaryuniversity_extensionWest Virginia University ExtensionView source ↗ Verified 2026-05-02 Position separates sulfur from nitrogen: nitrogen symptoms appear on the older lower leaves first, sulfur symptoms on the newer upper leaves.[2][2] Tier 1 · Primaryuniversity_extensionUniversity of Arizona Cooperative ExtensionView source ↗ Verified 2026-05-02
Frequently asked questions
What is the fastest way to tell nutrient deficiencies apart?
How do you tell nitrogen and sulfur deficiency apart?
Why does magnesium deficiency leave the veins green?
Is blossom end rot a calcium deficiency in the soil?
Curated from university research, peer-reviewed science, and manufacturer documentation, then verified claim by claim. Every factual statement on Meridian traces to a primary source.