Broccoli Nutrient Deficiency: Signs, Causes and the Fertilizer That Fixes It
Broccoli nutrient deficiency is one of the first things to check when the leaves of your brokoli (broccoli) turn yellow, purple or burnt at the edges. On Philippine farms the usual ones are nitrogen, boron, calcium, potassium, phosphorus, magnesium, sulfur and molybdenum. This guide shows where each one starts, how to be sure, and the fertilizer that fixes it.
Start with one question: did the change begin on the old leaves or on the young ones? Nitrogen, potassium, phosphorus, magnesium and molybdenum move inside the plant, so a shortage shows on the old, lower leaves first. But boron, calcium and sulfur stay where the plant first put them, so the young leaves and the growing tip show it first. After that, the color and the pattern narrow down which broccoli nutrient deficiency you have, and a soil test confirms it. Each one below has its signs, its causes and its fix.
Broccoli nutrient deficiency signs, old leaves and young leaves
Shows first on the old leaves
| Nutrient | Where it starts | What you see | Fix with |
|---|---|---|---|
| Nitrogen | old, lower leaves, the whole plant | Pale plants with orange to red edges on old leaves, and small, loose heads. | Urea 46 0 0, Ammonium sulfate 21 0 0 |
| Potassium | old, lower leaves, leaf edges and tips | Older leaves yellow, then brown from the edges with a sharp border. | Muriate of potash 0 0 60, Sulfate of potash 0 0 50 |
| Phosphorus | old, lower leaves, leaf edges and tips | Older leaves turn reddish from the edges with a yellow green band, in cold or dry soil. | Ammonium phosphate 16 20 0, Complete 14 14 14 |
| Magnesium | old, lower leaves, between the veins | Older leaves get a mottled yellow look between green veins, from the edges inward. | Magnesium sulfate (Epsom salt), Dolomite |
| Molybdenum | young leaves and the tip, leaf edges and tips | On acid soil, narrow, cupped young leaves with yellow, scorched edges in patches of the field. | Sodium molybdate, Ammonium molybdate |
Shows first on the young leaves
| Nutrient | Where it starts | What you see | Fix with |
|---|---|---|---|
| Boron | young leaves and the tip, fruit, grain or tubers | The stem is hollow with brown tissue inside, and new leaves look crinkled. | Borax, Solubor (sodium borate) |
| Calcium | young leaves and the tip, leaf edges and tips | Burnt, dead tips and edges on the youngest leaves. | Agricultural lime, Dolomite |
| Sulfur | young leaves and the tip, the whole plant | Young leaves turn pale, stiff and purplish, with narrow spoon shaped leaves on long stalks. | Ammonium sulfate 21 0 0, Gypsum |
Before you buy fertilizer for a broccoli nutrient deficiency
So use the table to pick the likeliest broccoli nutrient deficiency, then read its section below. Also keep in mind that dry soil, standing water, cold nights, a pest or a disease can look the same. That is why it pays to check the roots and the whole field first.
Nitrogen deficiency in broccoli
Leaves and heads turn evenly pale, starting on older leaves. Mature leaves yellow with orange to red color along the edges. Heads are small and loose, or do not form at all in severe cases. Plants are stunted and slow, with a higher risk of early bolting. You see it most at this stage: early leaf growth and again as the florets form. Broccoli needs nitrogen early, then a moderate supply at heading.
Why nitrogen deficiency happens in brokoli
Sandy soils, heavy rain or irrigation, low organic matter, raw straw or manure. A single unsplit dose that runs out before heading.
How to tell it apart
Red leaf edges can also come from phosphorus shortage. Phosphorus leaves are dark or bluish, nitrogen leaves are pale. To be sure, soil test and leaf tissue test.
What to apply for nitrogen deficiency
Side dress urea or ammonium sulfate in split doses based on the soil test. For a quick green up, try a urea spray at 10 grams per liter of water (160 grams in a 16 liter sprayer) every 15 days for cole crops such as cabbage. Side dress 1 to 2 bags of Urea 46 0 0 per hectare, about 5 grams a plant, two and four weeks after transplanting, and water it in.
- Urea 46 0 0
- Ammonium sulfate 21 0 0
- Complete 14 14 14
Sold here with nitrogen: Atlas Granular Urea (46 0 0) by Atlas Fertilizer, Crown Champion Ammonium Sulfate by Aqua Hydroponic Prime Ventures (21 0 0 with 24 percent sulfur), Agripower 46 0 0 (Locally Blended) Coated by Green Acres Agri Tech and Calcipro by Ramgo (15.5 0 0 with 18.8 percent calcium). Check the FPA registration on the bag and follow the label rate. For the how and when, see our guide to urea fertilizer, and the page on nitrogen deficiency in every crop. In anee.io, Anee, the smart farm technician, reads a photo of the leaf and tells you which nutrient is short.
To keep it away, give nitrogen early after transplanting and a second dose before heading. Keep organic matter up with compost, manure or crop residues.
Boron deficiency in broccoli
Watery tissue forms inside the stem and slowly turns brown or black, then dries out and leaves a hollow with brown patches. New leaves look crinkled and mottled, and plants are stunted with short spaces between leaves. Light brown spots can show on the head, and soft rot bacteria may enter the hollow stem. You see it most at this stage: head formation.
Why boron deficiency happens in brokoli
High soil pH, sandy soils where boron leaches, low organic matter, high nitrogen or calcium, drought or cold wet weather. Crucifers need more boron than most crops.
How to tell it apart
Hollowness from excess nitrogen or heat stays bright inside instead of browning. To be sure, cut stems lengthwise. Soil test and leaf tissue test for boron. In a soil test, less than 0.5 ppm of boron is low.
What to apply for boron deficiency
Before planting broccoli, mix up to about 2 kg of boron per hectare into the fertilizer. If no boron went in the soil, spray 1.1 to 1.7 kg of Solubor per hectare in plenty of water before heading. For cole crops, give borax at about 10 kg per hectare in the soil or a 1 gram per liter (16 grams in a 16 liter sprayer) spray. Do not overdo it. Too much boron burns leaf edges.
- Borax
- Solubor (sodium borate)
Sold here with boron: Etifert 11 (Borax Decahydrate) by Zetryl Chem (11 percent boron), Fertibagra 15G by Unilox Far East Resources (14.6 percent boron), B17 (Boric Acid) by Newman Chemicals (17 percent boron) and Better Yield by Bacphil Planters Fertilizer (0 0 0.9 with 10 percent boron). Check the FPA registration on the bag and follow the label rate. For the how and when, see our guide to foliar fertilizer, and the page on boron deficiency in every crop.
To keep it away, include boron in the basal fertilizer on sandy or limed soils. Test the soil every two or three years. Keep organic matter up with compost, manure or crop residues.
Calcium deficiency in broccoli
Young leaves are hit first, with dead lesions on the tips and edges that spread inward. Growth is restricted. You see it most at this stage: fast growth before and during heading.
Why calcium deficiency happens in brokoli
Restricted uptake more than low soil calcium: water stress, high ammonium, potassium, magnesium or sodium, and acid sandy soils.
How to tell it apart
Boron shortage also damages young leaves but brings hollow stems and crinkled leaves. To be sure, soil test for calcium, pH and boron.
What to apply for calcium deficiency
Keep the soil evenly moist. On acid soil, try lime at about 250 kg per hectare when pH is 5.5 to 6, or about 840 kg per hectare in two doses when pH is 3.5 to 4.5. Gypsum on soil that is not acid. Lime 2 to 4 weeks before planting. Calcium sprays go on young fruit from fruit set.
- Agricultural lime
- Dolomite
- Gypsum
- Calcium nitrate
Sold here with calcium: Micronized Activated Calcite by CMCS Agricultural Products (37.6 percent calcium), Dolomite by A6 Agrisource (24 percent calcium and 11 percent magnesium), Titon Pro by Vast Agro (27.2 percent calcium, 6.1 percent silicon and 3.6 percent magnesium) and Calcipro by Ramgo (15.5 0 0 with 18.8 percent calcium). Check the FPA registration on the bag and follow the label rate. For the how and when, see our guide to fertilizer for tomatoes, and the page on calcium deficiency in every crop.
To keep it away, lime before planting, water evenly and avoid heavy ammonium and potash. Test the soil every two or three years.
Potassium deficiency in broccoli
Older leaves turn yellow, then brown and dead, with a sharp border between dead and living tissue. The damage spreads from the edges inward, and in severe cases growth is badly stunted. Heads are smaller and of lower quality. You see it most at this stage: head formation and head enlargement, when broccoli needs the most potassium.
Why potassium deficiency happens in brokoli
Acid or sandy soils, heavy rain or irrigation, drought, low potassium reserves and soils rich in magnesium.
How to tell it apart
Magnesium shortage yellows between the veins first. Potassium burns the edges. To be sure, soil test for potassium and a leaf tissue test.
What to apply for potassium deficiency
Apply muriate of potash based on the soil test, in split doses before and at heading. For an immediate remedy on cole crops, try a morning spray of sulfate of potash at 10 grams per liter of water (160 grams in a 16 liter sprayer) with a sticker. A usual dose is 1 to 2 bags of Muriate of potash 0 0 60 per hectare, split between transplanting and the first side dress.
- Muriate of potash 0 0 60
- Sulfate of potash 0 0 50
- Complete 14 14 14
Sold here with potassium: Atlas Muriate of Potash (MOP) by Atlas Fertilizer (0 0 60), Simplot Sulfate 0 0 50 by Nutranta, Potassium Nitrate by Parafield (13 0 46) and Qrop Mix Production 14 0 23 plus 13 Cao by Farmtech Agriland (14 0 23 with 9.3 percent calcium). Check the FPA registration on the bag and follow the label rate. For the how and when, see our guide to potash fertilizer, and the page on potassium deficiency in every crop.
To keep it away, give potash before head formation. Keep organic matter up with compost, manure or crop residues.
Phosphorus deficiency in broccoli
Older leaves turn reddish starting at the edges, with a yellow green band between the red and the green. Early on leaf size is normal. In severe cases leaves and the whole plant stay small. You see it most at this stage: early growth, most often in cold soils or drought.
Why phosphorus deficiency happens in brokoli
Cold soils and drought, acid or calcareous soils, iron rich soils, low organic matter and weak roots. Broccoli is more sensitive to low phosphorus than cabbage or cauliflower.
How to tell it apart
Nitrogen shortage also reddens leaf edges but the leaves are pale overall. To be sure, soil test for available phosphorus and pH.
What to apply for phosphorus deficiency
Apply phosphorus near the roots based on the soil test. For cole crops use single superphosphate for a quick fix and rock phosphate or bone meal for the long term. A usual basal dose is 4 to 6 bags of Complete 14 14 14 per hectare, about 10 grams a hill, mixed into the soil at transplanting.
- Ammonium phosphate 16 20 0
- Complete 14 14 14
- Single superphosphate
Sold here with phosphorus: Philphos 18 46 0 (Di Ammonium Phosphate), Atlas Super Gro (16 20 0) by Atlas Fertilizer, Amigo Planters Granular Single Super Phosphate by La Filipina (0 18 0 with 11 percent sulfur) and Triple Super Phosphate by Newman Chemicals (0 46 0). Check the FPA registration on the bag and follow the label rate. For the how and when, see our guide to 16 20 0 fertilizer, and the page on phosphorus deficiency in every crop.
To keep it away, use a phosphorus starter at transplanting.
Magnesium deficiency in broccoli
Yellowing starts on older leaves and spreads between the veins from the edges inward. But the veins stay green and the leaf looks mottled. When it is bad, dead patches show up in the tissue between veins and around the leaf rim, and the plant stays small. You see it most at this stage: head formation.
Why magnesium deficiency happens in brokoli
Excess potassium, ammonium or calcium, sandy or acid soils, heavy potash fertilizer, and cold wet periods.
How to tell it apart
Potassium shortage can look similar. Magnesium usually yellows the whole area between veins before dead spots appear. To be sure, leaf tissue test plus soil test for magnesium and potassium.
What to apply for magnesium deficiency
For cole crops try magnesium sulfate in a band near the plants at about 80 kg per hectare. A foliar spray of magnesium sulfate gives faster relief. For quick help, spray Magnesium sulfate at 1 to 2 percent (160 to 320 grams in a 16 liter sprayer) two or three times, 10 to 14 days apart.
- Magnesium sulfate (Epsom salt)
- Dolomite
Sold here with magnesium: Dolomite by A6 Agrisource (24 percent calcium and 11 percent magnesium), Agsmart Kieserite Granule (20 percent sulfur and 16.3 percent magnesium), DDDD Planter's Choice Magnesium Sulphate Monohydrate by Modern Time (15.1 percent magnesium) and Zetryl MAG 9 by Zetryl Chem (9 percent magnesium). Check the FPA registration on the bag and follow the label rate. For the how and when, see our guide to complete fertilizer, and the page on magnesium deficiency in every crop.
To keep it away, use dolomite on acid soil. Test the soil every two or three years. Lime acid soil with Dolomite rather than plain lime.
Sulfur deficiency in broccoli
Yellowing starts in the youngest leaves, first between the veins and later evenly pale. Stems, leaf stalks and leaves may turn purple. Leaves become stiff, curl inward and grow narrow and spoon shaped on long stalks. Severe cases are badly stunted. You see it most at this stage: early growth.
Why sulfur deficiency happens in brokoli
Acid or sandy soils, low organic matter, waterlogged soils, and very high nitrogen, which can hold back sulfur uptake.
How to tell it apart
Nitrogen shortage starts on old leaves. Magnesium shortage also yellows between veins but on old leaves. To be sure, soil test for sulfate and a leaf tissue test. In a soil test, less than 10 ppm of sulfate sulfur is low.
What to apply for sulfur deficiency
Use ammonium sulfate as part of the nitrogen. For cole crops, try sulfur dust at about 25 kg per hectare on sulfur deficient soil. Give it at planting or with the first side dress.
- Ammonium sulfate 21 0 0
- Gypsum
- Elemental sulfur
Sold here with sulfur: Crown Champion Ammonium Sulfate by Aqua Hydroponic Prime Ventures (21 0 0 with 24 percent sulfur), Philphos Gypsum (22.2 percent calcium and 17.4 percent sulfur), Harvester Sulphate of Potash by Universal Harvester (0 0 50 with 17.5 percent sulfur) and Agsmart Kieserite Granule (20 percent sulfur and 16.3 percent magnesium). Check the FPA registration on the bag and follow the label rate. For the how and when, see our guide to ammonium sulfate fertilizer, and the page on sulfur deficiency in every crop.
To keep it away, give some sulfur every crop. Test the soil every two or three years. Keep organic matter up with compost, manure or crop residues.
Molybdenum deficiency in broccoli
The plant is stunted and its leaves stay pale, yellow green between the veins and out at the margins. Young leaves are narrow and distorted with edges that cup up or scorch, similar to whiptail in cauliflower. Affected plants usually come in patches. You see it most at this stage: seedling and young plant stage.
Why molybdenum deficiency happens in brokoli
Acid soils, mostly pH 5.5 or lower, and low organic matter.
How to tell it apart
Boron shortage also distorts young leaves. Nitrogen shortage gives pale plants without distorted leaves. To be sure, soil pH test. Spray sodium molybdate on a few plants as a test, then look for greener, normal new growth. A soil pH test confirms the risk.
What to apply for molybdenum deficiency
Mix about 50 grams of sodium molybdate in 100 liters of water. Spray it on the leaves, or pour 150 ml at the base of each plant. For the next crop, mix about 1 kg sodium molybdate per hectare with the fertilizer, or treat the seedbed with 40 grams in 50 liters per 10 square meters one to two weeks before transplanting. Spray Sodium molybdate at 0.05 to 0.1 percent (8 to 16 grams in a 16 liter sprayer) once or twice on young plants.
- Sodium molybdate
- Ammonium molybdate
- Agricultural lime
Sold here with molybdenum: Tierramino Molybdenum by Unilox Far East Resources (16 percent molybdenum) and YaraVita Teprosyn Mo (0 15 0 with 15.3 percent molybdenum). Check the FPA registration on the bag and follow the label rate. For the how and when, see our guide to foliar fertilizer, and the page on molybdenum deficiency in every crop.
To keep it away, lime acid soils to about pH 6 ahead of planting. Test the soil every two or three years.
A soil test is the surest check for any broccoli nutrient deficiency. Before you buy, ask your Municipal Agriculture Office where to send a soil sample. The DA regional soil laboratories test soil, and the result says how much of each fertilizer your brokoli needs. That saves money, because extra fertilizer is money lost.
Open the Nutrient Deficiency Finder, pick brokoli, say where the leaves changed first and what you see, and get the fertilizers sold here that fix it.
- Anee, the smart farm technician, reads a photo of the leaf
- The cropping calendar dates every fertilizer application of your season
Broccoli nutrient deficiency questions
Why are my brokoli leaves turning yellow?
What fertilizer fixes nitrogen deficiency in broccoli?
What fertilizer fixes boron deficiency in broccoli?
What fertilizer fixes calcium deficiency in broccoli?
How do I know which nutrient my brokoli lacks?
- Yara UK: Nitrogen deficiency in broccoli
- Yara UK: Boron deficiency in broccoli
- Yara UK: Calcium deficiency in broccoli
- Yara UK: Potassium deficiency in broccoli
- Yara UK: Phosphorus deficiency in broccoli
- Yara UK: Magnesium deficiency in broccoli
- Yara UK: Sulfur deficiency in broccoli
- NSW DPI Agfact AC.4: Molybdenum deficiency in plants
- Yara UK: Molybdenum deficiency in cauliflower
Find the missing nutrient and fix it
With Libre + Anee, read the whole guide: how to tell the deficiency from look alikes, how to be sure, what to apply, and the fertilizers sold here that supply it.
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