How to Grow Cardamoms USA

Growth Stages

Stage	BBCH	Notes
Potting and establishment	0	RHS: sow fresh seed with heat, or divide fleshy rhizomes; pot into loam-based, peat-free compost with added leaf mould or granulated bark. NC State: for indoor growing, use a pot at least 10in deep with good drainage, sandy-loamy soil amended with organic matter and well-rotted manure.
Vegetative growth under glass	3	RHS: keep in bright, filtered light, sheltered, with high humidity; pot on in spring as growth resumes. NC State: light should stay dappled to deep shade, avoiding direct sun; a pebble tray with regular misting keeps humidity up for indoor plants.
Flowering (tropical conditions only)	6	RHS: white, orchid-like flowers with purple, yellow or pink markings form on shoots spreading from the base in summer -- but only reliably under genuinely tropical conditions; UK conservatory/greenhouse plants mostly stay foliage-only. NC State agrees: flowers and fruit form only under tropical conditions, not from indoor or greenhouse growing alone.
Pod set and harvest	8	NC State: small pale green/yellow-green pods, 3/4in long, holding 15-20 aromatic seeds, develop after flowering and are hand-picked just before full ripeness to prevent splitting. RHS: remove flowered stems during spring pruning to keep the clump tidy for the next season.

Quick Facts

Factor	Value
Drainage	Loam-based, humus-rich, moist but well-drained (RHS); NC State: loamy/sandy-loamy, pH 5.5-6.8, tolerates occasional flooding.
Lifecycle	Evergreen rhizomatous perennial. RHS rates it H1B, needing 50-59°F (10-15°C) minimum -- essentially a UK conservatory/greenhouse or houseplant subject, not a hardy outdoor crop. NC State gives USDA zones 10a-13b and notes temperatures below 10°C (50°F) cause damage.
Edible parts	seeds

At a Glance

Harvest & Storage

When to pick: NC State: 3/4in yellow-green capsules holding 15-20 aromatic seeds; hand-pick just before full ripeness to stop pods splitting and losing flavour.

Storage

Used whole or ground in curry powders, meat preservation, and beverages (NC State).

Diseases

Cardamom virus diseases (unspecified/unidentified)

low

Named only vaguely by RHS ("plant viruses"), no species identified -- generic entry created rather than guessing a pathogen. NC State reports no known difficult disease problems.

Pests

Thrips

low

Thysanoptera

RHS: generally pest-free, but susceptible to thrips under glass. NC State reports no known difficult pest problems in warm-climate outdoor growing -- read as a genuine difference in growing context (greenhouse…

What university and government growers’ guides add about cardamom

Cardamom comes from tropical forest, so the question for a gardener outside the tropics is not when to sow it but whether you can give it the conditions indoors.

• It thrives in steady tropical rainforest conditions: NC State gives temperatures of 65 to 95°F (18 to 35°C) and humidity of about 75%. (NC State Extension)
• The sources set different cold limits. NC State and Missouri Botanical Garden say plants suffer damage below 50°F (10°C); Kew gives a minimum of 22°C and says it tolerates slightly colder places only briefly, if kept dry at the roots; Penn State gives an optimum annual mean of 22°C and says the plant will not grow below 17°C. (NC State Extension, Missouri Botanical Garden, Kew, Penn State)
• In temperate climates it needs a heated greenhouse or a warm, shady, humid place indoors. Missouri Botanical Garden adds that plants will not flower or fruit when grown outdoors in semi-tropical or temperate conditions, or indoors in pots. (Missouri Botanical Garden, Kew)
• It grows in shade with indirect light and dislikes draughts, sudden changes of temperature and direct sun. (Penn State, Kew)
• For a pot, NC State advises one at least 10 inches (25 cm) deep with drainage holes, filled with a loamy, well-drained but moisture-retaining mix at pH 5.5 to 6.8 and standing on a saucer of wet pebbles for humidity; keep the compost constantly moist but never let the pot sit in water. (NC State Extension, Missouri Botanical Garden)
• NC State suggests a high-nitrogen, low-potassium houseplant fertiliser twice a month. (NC State Extension)
• The fruits are labour-intensive to harvest and are typically picked by hand. (Missouri Botanical Garden)

Cardamom in the USA: climate data

Dates are the median 32°F freeze dates and freeze-free days from NOAA NCEI U.S. Climate Normals 1991–2020; zones come from the USDA 2023 Plant Hardiness Zone Map (ZIP code of each city centre).

The table shows how marginal the outdoors is. Every freeze-free figure above is measured at 32°F, while the sources put cardamom’s damage point at 50°F or higher, so a long freeze-free season does not make the garden warm enough. That is why the sources treat cardamom as a greenhouse or indoor container plant outside the tropics.

Sources for this section

• NC State Extension: True Cardamom, Elettaria cardamomum (Plant Toolbox)
• Missouri Botanical Garden: Elettaria cardamomum (Plant Finder)
• Royal Botanic Gardens, Kew: Elettaria cardamomum (L.) Maton, Plants of the World Online
• Penn State University (PlantVillage): Cardamom

Section researched and checked on 24 October 2026 by the SoilCommander Editorial Team. How we check facts: editorial policy.

Sources

1. North Carolina State University Extension (Plant Toolbox) - Elettaria cardamomum (Cardamom, Cardamon, Cardamum, Green Cardamom, True Cardamom)

   Light: dappled sunlight to deep shade; avoid direct sun. Soil: loamy/sandy-loamy, pH 5.5-6.8, well-drained but consistently moist, tolerates occasional flooding/wet soil. Size: 6-15ft height, 4-10ft width outdoors, rapid growth rate; indoor plants reach ~10ft in 5-10 years. Hardiness: USDA zones 10a-13b; temperatures below 50°F (10°C) cause damage. Native range: India, Burma, Sri Lanka. Propagation: division of fleshy, knobby rhizomes. Pests/diseases: no known difficult disease or insect problems. Harvest: 3/4in yellow-green capsules with 15-20 aromatic seeds, hand-picked before ripeness to prevent splitting; used in curry powder, meat preservation, and beverages. Indoor growing: pot at least 10in deep with drainage, sandy-loamy soil amended with organic matter and well-rotted manure, humidity tray of pebbles, regular misting.

These source is specific to this region. The full list of 2 sources behind this guide (North Carolina State University Extension (Plant Toolbox), Royal Horticultural Society) is in the references of our UK guide to cardamom; they describe the plant itself, which is the same wherever it grows.