How to Grow and Care for Cardamom

Cardamom (Elettaria cardamomum) hails from the ginger family and is most commonly grown for its seeds, which are used as a pungent, aromatic spice. This herbaceous perennial grows from thick, knobby underground rhizomes to produce an evergreen plant with erect, 6 to 15 cane-like stems with glossy, 24-inch, lance-shaped, dark green leaves.

In late spring or summer, leafless flowering stems emerge from the plant base to form 2-inch and yellowish-white flowers. The blooms are reminiscent of orchids, with lilac-purple veins and pink or yellow margins.

The flowers and stems are not scented but will produce pale yellowish-green 3/4-inch fruit pods. The pods contain 15 to 20 aromatic black to reddish-brown seeds, commonly used in Asian, Middle Eastern, and Scandinavian dishes and drinks.

How to Plant Cardamom

When to Plant

This rainforest native grows in the tropical areas of India, Myanmar, and Sri Lanka, typically places that receive about 150 inches of rain per year and temperatures that rarely dip below 70 degrees Fahrenheit. Plant outdoors when temperatures reach at least 70 F, depending on your region.

Bring the plant indoors when temperatures dip below 70 F. However, if you bring the plant indoors, it rarely flowers or produces seed pods.

Selecting a Plant Site

Plant cardamom in an edible garden with other shade-tolerant herbs, greens, or vegetables or in a rain garden where it will tolerate wet soil. The plants prefer rich, slightly acidic humus soil. Hardy in USDA zones 10 through 12, this herbaceous perennial is also suitable for growing in containers.

Spacing, Depth, and Support

If planting outdoors, plant your seeds 1/2 to 1 inch apart, about 1/8 inch deep, in a partially shady place. Alternatively, plant cardamom seeds in a pot to bring the plant indoors to overwinter. Staking is only needed for young plants if heavy rains or floods are expected, potentially washing the plants away.

Cardamom Plant Care

Light

Cardamom prefers part to full shade. Avoid planting in direct sun. Consider planting under tall trees in tropical conditions akin to its native rainforests.

Soil

Cardamom grows best in fertile, loam-based potting compost. If planting in bright, unfiltered light with high humidity, add leaf mold or granulated bark to the soil. Because cardamom needs tropical conditions to produce the optimal amount of fruit, it can thrive exceptionally well under glass. In the garden, it prefers acidic conditions (5.1-5.5 to 6.1-6.5).

Water

Mist cardamom frequently with rainwater; water regularly but do not overwater. Cardamom does best in sites where conditions are stable year-round, without much change to the climate, soil moisture, or natural light exposure.

Temperature and Humidity

Flowers and fruits will only grow in tropical conditions, so plant cardamom, where daily temperatures rarely go below 72 degrees Fahrenheit. Plant growth will suffer most dramatically if temperatures reach below 50 degrees Fahrenheit.

In semi-tropical or temperate climates, grow cardamom in a heated indoor greenhouse or a hot, steamy bathroom. While flowers and fruit rarely grow indoors, cardamom can make a lovely houseplant. Set the plant on a dish of consistently moist pebbles. The houseplant will grow much smaller than outdoors, to a humble 2 to 4 feet tall.

Fertilizer

Give the plant organic, high-phosphorus fertilizer twice a month during the growing season. Apply after heavy rain, never before. Supplement with compost once a year.

Pollination

Bees and other flying insects commonly pollinate cardamom plants. In places where bees are scarce, hand pollination is necessary. However, timing is crucial since flowers only stay open for about one day. Farmers use a small tool or brush to transfer pollen grains from the male anther to the female stigma. Signs that fertilization was successful include the flower wilting and the ovary swelling.

Types of Cardamom

Cardamom comes from the ginger family but has two main genus lines: Elettaria and Amomum. Lanxangia is a less commonly cultivated genus, more closely related to the Amomum genus.

• Green cardamom (Elettaria cardamomum): Also called true cardamom, Siam cardamom, or white cardamom, this type is native from India to Malaysia.
• Black cardamom (Amomum subulatum): Also called Indian cardamom, this type is native to Nepal and China.
• Lanxangia tsaoko (formerly Amomum tsaoko): Also called black cardamom, this Chinese and Vietnamese native plant is commonly used in Sichuan cooking.
  

Green Cardamom vs. Black Cardamom

Green and black cardamom are used for flavoring foods, although green cardamom will also be used in sweets. Green cardamom has a sweeter, eucalyptus-type flavor, while black cardamom has a more robust, smokier flavor. With rich camphor or more menthol-like notes, black cardamom is best used in savory stews and curries.

Harvesting Cardamom

The best way to harvest this plant is to hand-pick each seed pod or fruit. Harvest when the seed pod is beginning to split. You also know it's ready for picking if the seed pod pulls away easily from the plant when you tug at it.

Cardamom is the third most expensive spice by weight, just behind saffron and vanilla. There is a long history of trade and consumption for more than 1,000 years. In the early 1900s, German coffee planter Oscar Majus Kloeffer introduced cardamom to Guatemala. Until about 1980, India was the largest producer and exporter of cardamom until Guatemala took the lead.

While cardamom is used around the globe, some of the main consumers are Middle Eastern countries, where the spice is often added to warm beverages, and Scandinavian countries, where it is often added as flavoring to cookies and cakes.

As the primary ingredient in curry powder, cardamom can flavor rice, meat, vegetables, liquors, and ice cream. Guatemala and Mexico now use it to flavor chewing gum. In addition to culinary uses, cardamom is also used in cosmetics and perfumery.

When storing cardamom, prevent air and oxygen exposure by keeping it in airtight containers, such as tight-fitting lids or vacuum-sealed bags. These methods preserve the freshness and potency of cardamom longer. Also, keep cardamom cool and dry, away from sunlight or heat sources.

How to Grow Cardamom in Pots

Cardamom grows well in pots. Start seeds with very moist soil. Plant them at least 1 inch apart. Each plant needs a pot at least 1 foot deep and 6 inches wide. If you plant multiple seeds in each 6-inch pot, only keep the strongest seedling and remove the others.

Since this plant gets stressed during transplanting, it's best to grow it in a pot that is 12 to 14 inches wide to accommodate its full growth indoors. Ensure the container has ample drainage holes.

If you live in a climate that gets wintery cold weather, bring the plant inside when temperatures drop to the 60s F. Most people grow the plant in the most humid part of the house, often the bathroom. When grown indoors, the plant rarely grows past 4 feet tall unless grown in a greenhouse.

Pruning

Cardamom doesn't need pruning, although removing dead or damaged leaves is fine by cutting the withered or old flower stems. Also, if the plant is growing larger than you like, trim it down to a size you prefer.

Propagating Cardamom

Propagate by dividing the rhizome root structure or by sowing seed. Consider dividing every three years so the rhizome does not overgrow its container or plot.

To divide, here's how:

1. Loosen the soil around the parent plant using a trowel and hand rake.
2. Lift the rhizomatous roots from the ground.
3. Use a sharp knife or a root saw to separate or split off a rhizome segment with at least four to five leaf shoots.
4. Plant the segment elsewhere and replant the parent plant where it was.
   

How to Grow Cardamom From Seed

Purchase cardamom designed explicitly for planting, or if you have a mature plant that produces seeds, let the seed pods dry on the plant, then break them open to collect the seeds. Sow them as soon as you collect them from the plant.

Presoak cardamom seeds overnight before planting. Plant the seeds in a warm, partially shady spot in loamy, rich soil. Expect germination to take about 30 to 40 days.

Potting and Repotting Cardamom

Cardamom gets stressed from transplanting, so it's best to grow cardamom in the container it will mature in. However, cardamom grows from a rhizome that can grow large and be divided after three to four years.

To transplant a segment of the cardamom rhizome, get a similarly sized container and use moist, loamy soil to repot a piece of the cardamom with several leaf sheathes.

Overwintering

If your plant is kept outdoors during the warm summer temperatures, bring the plant indoors when the temperatures drop between 60 to 70 F. The plant gets stressed in cold temperatures and will die. Bring cardamom plants indoors during the late fall, winter, and early spring, and keep the plants in the most humid part of the house with filtered light. Bathrooms are one of the best spots for cardamom plants.

In the colder months, from October to March, withhold fertilizer—also, water only when the soil is dry. The plant requires humidity, so keep the plant moist by misting, if necessary.

Common Pests and Diseases

While the cardamom plant is generally free from pests and disease, it may be affected by thrips or cardamom mosaic virus. Aphids spread the virus, so prevent the virus by keeping aphids away with a forceful water spray, insecticidal soap, or neem oil.