🌾 Fertiliser Guide · Fact Checked · April 2026

Best Fertiliser for Cardamom:
NPK Guide, Schedule & Deficiency Fixes

The exact NPK ratios cardamom needs, when to switch to potassium-rich tomato feed, how to use Epsom salt for magnesium, and a dose calculator for your pot size — all backed by Spices Board India and ICRI data.

✍️Written byOlivia Turner
Fact checkedEmily Rhodes
📅PublishedApril 2026
⏱️Read time13 min
🔬SourcesSpices Board India · ICRI · KAU · NIPHM
Olivia Turner
Written by
BSc Horticulture · Spice Plant Specialist
Olivia has grown and researched tropical spice plants for over a decade, with a focus on Elettaria cardamomum cultivation in temperate climates.
View full profile →
Emily Rhodes
Reviewed by
Nutrition & Culinary Specialist
Emily reviews all CardamomNectar content for nutritional and botanical accuracy, drawing on her background in food science and plant nutrition.
View full profile →
⚡ Quick Answer — Featured Snippet

Cardamom needs a balanced NPK fertiliser (10:10:10) monthly from April–September, switching to a potassium-rich feed (tomato feed or 5:10:15 NPK) from June onwards when flowering begins. Add magnesium sulfate (Epsom salt) monthly as a foliar spray — ICRI soil surveys found magnesium deficiency widespread in cardamom-growing soils. Apply zinc sulfate foliar spray twice yearly. Stop all feeding October–March. Never use high-nitrogen feeds as your only fertiliser — excess nitrogen suppresses flowering.

Cardamom Fertiliser — Key Facts from ICRI & Spices Board India

These numbers come directly from the Indian Cardamom Research Institute (ICRI) and Spices Board India — the world’s foremost authorities on Elettaria cardamomum cultivation.

75:75:150
NPK kg/ha recommended (N:P:K) — Spices Board India
Potassium need is double nitrogen — cardamom is a heavy K feeder
May/Jun
+ Sep/Oct
Two feeding times recommended by Spices Board India
Mg + S
Deficiencies widespread in cardamom soils — ICRI 2024
📌 Spices Board India guidance (CardSApp): “Common fertilisers used in cardamom plantations are Urea (N-46%), Rock phosphate (P₂O₅ 16-18%) and Muriate of Potash (K₂O-60%). Magnesium Sulphate and Zinc sulphate are common sources of secondary and micronutrients. Apply fertilisers in May/June and September/October with sufficient moisture in soil.” This is the benchmark for all cardamom fertiliser decisions.

What Each Nutrient Does for Cardamom

Understanding why cardamom needs each nutrient tells you exactly when to prioritise which fertiliser type — and why the standard “balanced NPK and nothing else” approach leaves money on the table.

Nitrogen fertiliser for cardamom vegetative growth
N — Nitrogen

Nitrogen — Cane & Leaf Growth

Nitrogen drives vegetative growth — the tall canes, large leaves and overall plant size. Young plants (years 1–2) need a nitrogen emphasis to build structure. Mature plants need moderate nitrogen, balanced with potassium. Excess nitrogen on a mature plant produces abundant leafy canes at the direct expense of flowering and pod production. Never use a high-nitrogen feed as your primary fertiliser on a plant over 2 years old.

Source: Urea (46% N), balanced NPK, blood mealSeason: April–May primary application
Phosphorus fertiliser for cardamom root development
P — Phosphorus

Phosphorus — Root & Flower Structure

Phosphorus supports root development and the structural formation of flowers and pods. Commercial growing uses Single Super Phosphate (SSP) or Di-Ammonium Phosphate (DAP). An ICRI 2024 soil survey found that most cardamom-growing soils actually have high phosphorus availability — which means excess phosphorus application is wasteful and can create nutrient lockout. A balanced NPK provides adequate P without over-application.

Source: SSP, DAP, balanced NPK, bone mealNote: Often adequate in soil — don’t over-apply
Potassium fertiliser for cardamom pods and essential oil
K — Potassium

Potassium — Pods, Oil & Disease Resistance

Potassium is cardamom’s most important macronutrient — commercial guidelines recommend double the potassium of nitrogen (150kg K vs 75kg N per hectare). Potassium drives pod formation, improves essential oil content (which determines flavour and market value), strengthens cell walls for disease resistance, and supports efficient photosynthesis. Switch to a potassium-heavy feed (tomato feed or MOP supplement) from June when panicles appear.

Source: Muriate of Potash (MOP), tomato feed, SOPEssential from June — don’t skip this switch
Magnesium sulfate Epsom salt for cardamom
Mg — Magnesium

Magnesium — Chlorophyll & Essential Oil

Magnesium is the central atom of chlorophyll molecules — without it, photosynthesis collapses. The Spices Board India flags magnesium deficiency as widespread in cardamom soils. Beyond chlorophyll, magnesium also enhances essential oil content in pods, which directly affects flavour quality. The standard fix is Epsom salt (magnesium sulfate) — either as a monthly foliar spray or incorporated into the soil. Monthly application prevents the interveinal chlorosis that growers often misdiagnose as iron deficiency.

Source: Epsom salt (MgSO₄), dolomite limeApply monthly April–Sep as foliar spray

Complete Cardamom Fertiliser Schedule — Month by Month

This schedule applies the Spices Board India’s two-period application principle to a home-growing context — adapted for container plants and temperate climate growers.

MonthFeed TypeApplicationWhyFeed?
January–MarchNoneSemi-dormant period — roots cannot process nutrients✕ Stop
AprilBalanced NPK (10:10:10)Monthly liquid feed at half strength to startRestart feeding as growth resumes — ease in gently✓ Start
MayBalanced NPK + Epsom salt foliarFull-strength NPK liquid + Epsom spray (1 tbsp/4L)Active growth phase — nitrogen emphasis for new canes✓ Active
JuneBalanced NPK + K supplement + Epsom foliarBalanced feed + tomato feed or potassium boost monthlyPanicle initiation — switch emphasis to potassium now✓ Switch
July–AugustPotassium-rich (tomato feed) + Epsom foliarK-rich liquid monthly + Epsom spray monthlyFlowering and pod development — peak potassium need✓ Peak K
SeptemberFinal K feed + zinc sulfate foliarTomato feed + zinc spray (0.25% zinc sulfate)Late season pod fill — zinc enhances oil content per ICRI✓ Final
OctoberStop all feedingFlush soil with plain water onceGrowth winding down — feeding now causes root burn✕ Stop
November–DecemberNoneDormancy period — roots inactive✕ None
⚠️ Do not mix magnesium sulfate with NPK fertiliser in the same application. The Spices Board India specifically warns: “Avoid mixing NPK mixtures along with Magnesium Sulphate.” Apply NPK one week, Epsom salt foliar spray the following week. Also maintain a 2–3 week gap between lime and any fertiliser application.

Cardamom Fertiliser Dose Calculator

Enter your pot size, plant age and current growth stage — get the exact liquid fertiliser dose for this month, Epsom salt quantity, and a personalised monthly schedule. Takes the guesswork out of feeding your cardamom.

🌾 Fertiliser Dose Calculator

Calculates exact monthly doses for your specific plant and pot — no guessing, no overfeeding.

Your Monthly Feeding Plan

Cardamom Nutrient Deficiency — Visual Guide

Each nutrient deficiency produces a distinct visual pattern on cardamom foliage. Identify what you’re seeing, then apply the targeted fix — not just “more fertiliser.”

Cardamom nitrogen deficiency pale uniform yellowing
Nitrogen Deficiency
Uniform Pale Yellowing — Older Leaves First

Pale yellow-green colour spread uniformly across older lower leaves. Young leaves at the top remain greener. Slow, stunted growth. Thin, weak new canes. Common in plants that haven’t been fed for 8+ weeks in the growing season, or those potted in spent, exhausted soil.

Apply balanced liquid NPK at normal dose. Improvement visible within 7–10 days on newer leaves.
Cardamom magnesium deficiency interveinal chlorosis
Magnesium Deficiency
Interveinal Chlorosis — Yellow Between Green Veins

Yellow patches develop between the leaf veins, while the veins themselves remain distinctly green — this interveinal pattern is the diagnostic signature of magnesium deficiency. The ICRI 2024 soil survey found this is the most widespread micronutrient problem in cardamom-growing areas. Also caused by overuse of high-potassium feeds which lock out magnesium uptake.

Foliar spray: 1 tablespoon Epsom salt per 4 litres water. Apply weekly for 3 weeks, then monthly. Results visible within 10–14 days.
Cardamom zinc deficiency small pale new leaves
Zinc Deficiency
Small, Pale New Leaves — Stunted Growing Tips

New leaves emerge unusually small and pale, with shortened internodes making the growing tips look dense and stunted. Zinc deficiency reduces essential oil content in cardamom pods — a direct quality issue. The Spices Board India recommends zinc sulfate foliar spray twice annually (April/May and September/October) as a standard preventive measure in all cardamom growing.

Foliar spray: 0.25% zinc sulfate solution (2.5g per litre water). Apply twice in spring and once in September. Do not mix with any other spray.
Cardamom fertiliser burn from overfeeding
Fertiliser Burn (Over-feeding)
Brown Leaf Tips + White Salt Crust on Soil

Paradoxically, too much fertiliser creates nutrient deficiency symptoms. Salt build-up from over-application draws water out of roots (osmotic stress), causing brown leaf tips, wilting despite moist soil, and a white crystalline crust on the soil surface. This is particularly common in winter when growers continue summer feeding rates on a semi-dormant plant.

Flush soil with 3–4 volumes of plain water to leach salts. Stop feeding for 4–6 weeks. Resume at half-strength dose.

Cardamom Deficiency Symptom Checker

Select what you’re seeing on your plant — get an instant diagnosis, the most likely deficiency or problem, and exact steps to fix it. Based on ICRI and Spices Board India diagnostic criteria.

🔍 Deficiency Symptom Checker

Describe your plant’s symptoms — get a diagnosis and targeted fix in seconds.

Diagnosis

Organic Fertilisers for Cardamom

Cardamom is naturally grown in forest understory conditions rich in decomposing organic matter. Organic fertilising closely mimics this environment and improves long-term soil health.

Organic fertiliser options for cardamom plant
Spices Board India organic recommendations: “Application of mature farmyard manure/compost at 5–10kg per plant in May/June. Organic manures such as neem cake (1kg per plant), bone meal (1kg per plant) or vermicompost (1kg per plant) have beneficial effects on root proliferation and also help reduce nematode and root grub infestation.”

Best organic options for home growers

🪱 Worm castings (vermicompost)
Replace 10% of potting mix with worm castings, or top-dress 2–3 tbsp around the base monthly. Rich in micronutrients, beneficial bacteria and humic acids. Almost impossible to over-apply.
🌿 Neem cake
ICRI-recommended organic amendment. Adds slow-release N (2–3%), improves root health, and suppresses soil nematodes. Mix 1 tsp into the top layer of pot soil monthly in the growing season.
🌊 Liquid seaweed extract
High in potassium, trace minerals and plant growth hormones (cytokinins and auxins). Use as a monthly drench at 5ml per litre. Supports root development and stress recovery. Excellent as a transplant shock recovery treatment.
🌾 Comfrey liquid feed
DIY high-potassium feed: soak comfrey leaves in water for 3–4 weeks, dilute 1:10 with water. Apply monthly June–September. Excellent potassium source for flowering support — the organic equivalent of tomato feed.
🦴 Bone meal
Slow-release phosphorus (15–20% P₂O₅) and some calcium. Spices Board India recommends 1kg per plant annually. For containers, mix 1 tablespoon into the top layer of soil in spring. Do not over-apply — excess phosphorus locks out zinc and iron.

Best Fertilisers to Buy for Cardamom

Products we recommend based on the specific nutritional needs of Elettaria cardamomum — not generic plant food suggestions.

Balanced NPK liquid fertiliser

Balanced Liquid NPK (10:10:10)

The April–May base feed. Monthly application at label rate from the restart of growth. Do not skip — this establishes the foundation for the whole season.

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High potassium tomato fertiliser for cardamom

High-Potassium Tomato Feed

The June–September supplement. Switch to this when panicles appear. High potassium (K) directly supports pod formation, essential oil content and disease resistance in cardamom.

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Epsom salt magnesium sulfate for cardamom

Epsom Salt (Magnesium Sulfate)

Monthly foliar spray April–September. ICRI confirmed magnesium deficiency is widespread in cardamom soils. 1 tablespoon per 4 litres — don’t mix with NPK feed in same application.

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Liquid seaweed fertiliser for cardamom

Liquid Seaweed Extract

Monthly drench for trace minerals, cytokinins and potassium. Ideal as a gentler alternative between NPK feeds, or as a transplant/recovery tonic after repotting.

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Worm castings for cardamom

Worm Castings (Vermicompost)

ICRI-recommended organic amendment. Top-dress monthly or incorporate into the potting mix. Almost impossible to over-apply — safe for all growth stages including seedlings.

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Neem cake organic fertiliser for cardamom

Neem Cake

Spices Board India-recommended amendment. Slow-release N, improves root health and suppresses soil nematodes. Mix 1 tsp into top soil monthly during the growing season.

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As an Amazon Associate CardamomNectar earns from qualifying purchases. Our recommendations are based solely on what works for Elettaria cardamomum.

Cardamom Fertiliser — 20 Expert Answers

Every fertilising question cardamom growers ask — answered with specifics, not generalities. LSI keywords covered: NPK ratio, tomato feed, Epsom salt, worm castings, seaweed, liquid feed, slow release, organic, deficiency, schedule.

The best fertiliser programme combines: (1) Balanced liquid NPK (10:10:10) monthly April–May for vegetative growth; (2) Switch to potassium-rich tomato feed or 5:10:15 NPK from June onward to support flowering and pod formation; (3) Monthly Epsom salt foliar spray (1 tbsp per 4L water) for magnesium; (4) Zinc sulfate foliar spray twice yearly in April and September per Spices Board India guidance. No single fertiliser covers all cardamom’s needs — the two-phase approach (balanced spring, K-heavy summer) is what separates productive plants from non-flowering ones.
Cardamom has a potassium-weighted NPK requirement. The Spices Board India’s commercial recommendation is 75:75:150 kg/ha (N:P:K) — meaning potassium (K) should be double nitrogen (N). For home container growing, a 10:10:10 balanced feed works well in April–May, switching to a 5:10:15 or tomato-feed ratio (typically 4:3:8 or similar) from June. The potassium-heavy second phase directly drives pod formation, essential oil content and disease resistance — this is the most commonly skipped step by home growers.
Yes — tomato feed (high-potassium liquid fertiliser) is one of the best supplements for cardamom from June onwards when panicles appear. Cardamom’s commercial growing guidelines specify a potassium recommendation double that of nitrogen — exactly the K-heavy ratio tomato feeds provide. Use it monthly as your primary liquid feed from June to September, either alongside or instead of your balanced NPK. Do not use tomato feed as the only fertiliser from the start of spring — the plant needs more nitrogen early in the season to build new canes and leaves.
Monthly during the active growing season: April to September. In April, restart at half-strength. From May, apply at full label rate. Monthly means once every 4 weeks — not every watering and not every 2 weeks. In addition to the monthly NPK feed, apply Epsom salt foliar spray separately on a different week each month. Apply zinc sulfate spray twice in the season (April/May and September). Stop all feeding completely from October to March — the plant’s root activity drops significantly and feeding winter cardamom causes salt burn.
Yes — monthly Epsom salt (magnesium sulfate) application is recommended for cardamom. The ICRI 2024 soil survey found magnesium and sulfur deficiency widespread in cardamom-growing areas, and the Spices Board India lists magnesium sulfate as a standard amendment. Apply as a foliar spray: dissolve 1 tablespoon (15g) in 4 litres of water and spray leaves in the morning, monthly April–September. Do not apply in the same week as your NPK fertiliser — the Spices Board India specifically warns against mixing magnesium sulfate with NPK applications.
Interveinal chlorosis (yellow between green veins) appearing after starting tomato or high-K feeds is caused by potassium locking out magnesium uptake. Potassium and magnesium ions compete for the same root absorption pathways — very high potassium concentrations outcompete magnesium, creating visible deficiency even when magnesium is present in the soil. The fix is to apply Epsom salt foliar spray immediately (bypasses soil absorption competition) and either reduce the potassium feed frequency or alternate it with a balanced feed. Do not abandon the potassium feed entirely — the plant still needs it for pod production.
Yes — worm castings (vermicompost) are an excellent organic amendment for cardamom. The Spices Board India recommends vermicompost at 1kg per plant. They provide a wide range of micronutrients, beneficial soil microbes, and humic acids that improve root health and nutrient uptake. For container plants, top-dress 2–3 tablespoons around the base monthly, or replace 10% of your potting mix with worm castings when repotting. They are almost impossible to over-apply, making them safe to use freely — unlike synthetic fertilisers where excess causes burn.
Yes — liquid seaweed extract is an excellent supplement for cardamom. It provides potassium, trace minerals (copper, zinc, boron, molybdenum), and natural plant hormones (cytokinins and auxins) that support root development and stress recovery. Apply as a monthly soil drench at 5ml per litre of water throughout the growing season. It works particularly well as a recovery treatment after repotting, after pest damage, or after a period of neglect. It can be used in addition to your regular NPK feeding — not as a replacement for it.
Signs of cardamom fertiliser burn: brown or scorched leaf tips (starting at the very tip and working inward); white crystalline crust on the soil surface (salt accumulation); wilting despite adequate watering; and root damage visible as brown root tips when repotting. If you see these symptoms, immediately flush the soil thoroughly with 3–4 full pot-volumes of plain water to leach excess salts. Stop feeding for 4–6 weeks. Resume at half the standard dose and build back up gradually. The most common cause is feeding during winter dormancy (October–March) when roots cannot process nutrients.
Yes — this is one of the most common reasons mature cardamom plants fail to flower. Excess nitrogen redirects the plant’s energy into vegetative growth (producing abundant dark green canes and large leaves) at the direct expense of reproductive growth (flowers and pods). Plants grown with high-nitrogen fertilisers as their primary feed through the season often produce spectacular foliage but zero flowers. The fix is to switch from any high-N feed to a balanced or potassium-heavy feed from June onwards, and avoid high-nitrogen fertilisers (like those marketed for tropical foliage plants) after year 2 of growth.
The Spices Board India (CardSApp) recommends: farmyard manure or mature compost at 5–10kg per plant applied in May/June; neem cake at 1kg per plant (also suppresses soil nematodes); bone meal at 1kg per plant; and vermicompost at 1kg per plant. For home container growers, the equivalent is top-dressing with worm castings monthly, mixing neem cake into the potting mix at each repotting, and applying liquid seaweed as a monthly drench. These organic sources release nutrients slowly and improve soil microbiology in ways synthetic fertilisers cannot.
Seedlings (under 1 year): no fertiliser for the first 3 months — use only fresh potting mix. After 3 months, apply balanced NPK at quarter-strength monthly. Young plants (1–2 years): balanced NPK at half to full strength monthly April–September. Nitrogen emphasis is appropriate as the plant builds its cane structure. Do not push potassium heavily at this stage — the plant cannot yet flower. Mature plants (3+ years): balanced NPK April–May, then switch to potassium-heavy feed June–September. Add Epsom salt monthly. This is when the two-phase feeding approach becomes critical for flowering.
No — stop all fertilising completely from October to March. During this period, cardamom enters semi-dormancy: root activity drops significantly, growth slows, and the plant’s ability to absorb and process nutrients is severely reduced. Fertilising a dormant or semi-dormant cardamom is wasteful at best and harmful at worst — excess fertiliser accumulates as salt in the soil and can cause root burn. When you restart feeding in April, begin at half-strength for the first application to allow roots to readjust after the dormant period.
The Spices Board India (via CardSApp) recommends two application periods: May/June and September/October. The full commercial recommendation is 75kg N + 75kg P + 150kg K per hectare annually, applied in two equal split doses. Magnesium sulfate, bentonite sulfur, and zinc sulfate are listed as standard secondary and micronutrient applications. For home growers, this translates to: April/May = balanced NPK + Epsom salt; June/July/August = tomato feed + Epsom salt; September = final feed + zinc sulfate spray; October = stop completely.
Slow-release granular fertiliser (like Osmocote or similar) can be used for cardamom but with caveats. They provide a consistent background feed but do not allow you to switch ratios (e.g. from balanced to potassium-heavy) through the season, which is important for flowering. If using slow-release, choose a product with a potassium-weighted ratio (like a 6:3:9 or similar) rather than a balanced one. Apply in spring and supplement with liquid tomato feed from June onwards for potassium. Add Epsom salt foliar spray monthly regardless — slow-release fertilisers do not adequately address magnesium needs.
Yes — neem cake is a Spices Board India-recommended amendment for cardamom specifically. It provides slow-release nitrogen (2–3%), improves root health, and suppresses soil nematodes and root grubs which are significant pests in cardamom cultivation. For container plants, mix 1 teaspoon of neem cake into the top 2–3cm of potting soil monthly during the growing season. At repotting, incorporate 1–2 tablespoons into the new mix. It does not replace NPK liquid feeding but is an excellent supporting amendment that improves soil biology over time.
Cardamom benefits from three types of foliar spray: (1) Magnesium sulfate (Epsom salt) — 1 tbsp per 4 litres, monthly April–September, to prevent the widespread magnesium deficiency ICRI confirms in cardamom soils; (2) Zinc sulfate — 0.25% solution (2.5g per litre), twice per year in April/May and September per Spices Board India guidance — zinc enhances essential oil content; (3) Balanced liquid NPK or seaweed — optional foliar application at very dilute rates for a quick nutrient boost. Never mix multiple spray types in the same application. Apply all foliar sprays in the morning when temperatures are cooler.
Yellowing after fertilising typically indicates one of three things: (1) Fertiliser burn from over-application — check for white salt crust on soil surface; flush with plain water; (2) Potassium-induced magnesium deficiency — if yellowing is between green veins (interveinal chlorosis) and you recently started tomato feed, apply Epsom salt foliar spray immediately; (3) Root damage from excess salts affecting water uptake — this shows as uniform wilting and yellowing. If in doubt, flush the soil thoroughly, wait 2 weeks, and restart at half-strength. Never apply more fertiliser to a plant already showing fertiliser burn symptoms.
Coffee grounds can be used sparingly for cardamom — they are mildly acidic (pH 6.0–6.5 when brewed, closer to neutral when dry) and provide small amounts of nitrogen, potassium and magnesium. Sprinkle a thin layer (no more than 0.5cm) on the soil surface monthly. Do not over-apply — thick layers of coffee grounds can compact and create a water-repellent crust, and excess nitrogen from regular application can suppress flowering. Grounds work better as a component of a compost mix than as a direct soil amendment. They should supplement, not replace, a balanced NPK feeding programme.
Do not fertilise for at least 3–4 weeks after repotting into fresh soil. Fresh potting mix contains nutrients from its compost component — adding fertiliser on top can cause root burn on already-stressed roots. Water in with diluted liquid seaweed solution (5ml per litre) immediately after repotting to reduce transplant stress without adding heavy salts. Keep in reduced light for 1 week to lower the plant’s stress response. After 4 weeks, resume normal monthly feeding at half-strength, building back to full strength over the following month.
Olivia Turner
Written by
BSc Horticulture · Spice Plant Specialist · Oregon State University

Olivia writes all growing and plant-related content on CardamomNectar. With a BSc in Horticulture from Oregon State University and over a decade spent growing tropical spice plants, she brings rigorous academic grounding and practical hands-on experience to every guide. She has grown cardamom in controlled greenhouse conditions and in temperate outdoor settings.

View all articles by Olivia →
Emily Rhodes
Reviewed by
Nutrition & Culinary Specialist · Content Reviewer

Emily reviews all CardamomNectar content for botanical and nutritional accuracy before publication. Her background in food science and plant nutrition ensures every fertiliser recommendation, nutrient claim and deficiency diagnosis is cross-checked against current horticultural and agronomic literature. She also writes all recipe, health and tea-related content on the site.

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