1. Introduction

Calatheaare popular houseplants prized for their leaves with graphic patterns and vibrant colors. Belonging to the Marantaceaefamily, they are native to the tropical forests of South and Central America. Their care requires a certain level of attention, particularly regarding humidity and light, which makes them suitable plants for experienced gardeners or enthusiasts of tropical plants.

This guide covers all aspects of Calathea, including biological, historical, cultural, commercial, and health-related aspects, with practical advice for both amateurs and professionals.

2. Biology and Classification

2.1. Taxonomy and Family

• Kingdom:

• Plantae

• Clade:

• Angiosperms

• Clade:

• Monocots

• Order:

• Zingiberales

• Family:

• Marantaceae

• Genus:

• Calathea

• Common Species:

• Calathea orbifolia

• (round leaves)

• Calathea lancifolia

• (narrow, elongated leaves)

• Calathea makoyana

• (peacock-shaped leaves)

• Calathea rufibarba

• (velvety leaves)

• Calathea zebrina

• (striped leaves)

• Calathea crocata

• (known for its bright orange flowers) Source: Wikipedia - Calathea

  2.2. Morphological Characteristics

• Habit:

• Herbaceous perennial plant, often acaulescent (without a visible stem), with leaves emerging directly from the ground via petioles.

• Leaves:

• Shape:

• Variable depending on the species (oval, lanceolate, round, arrow-shaped).

• Color:

• Green with complex patterns (stripes, spots, marbling) in light green, dark green, purple, pink, or silver.

• Texture:

• Some species have velvety leaves (

• C. rufibarba

• ), while others are smooth and glossy.

• Movement:

• The leaves fold up at night (nyctinasty), a phenomenon related to light and humidity.

• Flowers:

• Relatively inconspicuous in most species, but some, like

• C. crocata

• , produce bright orange inflorescences. The flowers are generally small and grouped in spikes.

• Roots:

• Underground rhizomes that store nutrients.

  2.3. Physiology and Ecological Needs

• Photosynthesis:

• Plants are

• C3

• (unlike C4 or CAM plants, they do not have a mechanism for concentrating CO₂).

• Humidity:

• Requires high atmospheric humidity (70-90%) to prevent leaf desiccation.

• Light:

• Prefers

• indirect and subdued light

• (ideally 1,000–2,000 lux). Direct light can burn the leaves.

• Temperature:

• Optimum between

• 18°C and 25°C

• . Avoid drafts and temperatures below 15°C.

• Substrate:

• Well-drained soil, rich in organic matter (a mixture of peat, perlite, and compost). Source: Missouri Botanical Garden - Calathea

  3. History and Discovery

3.1. Geographical Origin

Calathea plants are native to the humid tropical forestsof South and Central America, including:

• Brazil
• (Amazon region)
• Colombia
• Costa Rica
• Peru
• Ecuador

These regions offer a warm and humid climate, which is conducive to their growth.

3.2. Discovery and Introduction to Europe

• The first

• Calathea

• species were described by European naturalists in the

• 19th century

• , during scientific expeditions to South America.

• The genus

• Calathea

• was established by

• Augustus Pyramus de Candolle

• in 1821.

• Calathea plants became popular as houseplants in Europe and North America in the

• 20th century

• , thanks to their decorative foliage.

  3.3. Historical and Cultural Uses

• Utility plants:

• Some species were used by indigenous peoples for their fibers (leaves of

• Calathea lutea

• used to make baskets).

• Traditional medicine:

• Certain varieties were used for their anti-inflammatory properties or to treat headaches (limited use, poorly documented scientifically).

• Ornamental plants:

• Today, they are primarily cultivated for their aesthetic value in interiors and tropical greenhouses. Source: Kew Royal Botanic Gardens - Calathea

  4. Care and Maintenance

4.1. Ideal Growing Conditions

4.2. Watering and Water Quality

• Soft Water:

• Calatheas are sensitive to

• lime

• and

• chlorine

• . Use water that is:

• Rainwater

• (ideally)

• Filtered

• or

• demineralized

• Tap water left standing for 24 hours

• (to evaporate the chlorine)

• Frequency:

• Water when the

• top centimeter of the substrate is dry

• . Avoid standing water in the saucer (risk of root rot).

  4.3. Fertilization

• Period:

• Spring and summer (active growth period).

• Fertilizer:

• Use a

• liquid, balanced fertilizer

• (NPK 10-10-10 or 20-20-20)

• diluted by half

• every

• 2–4 weeks

• .

• Winter:

• Reduce or stop fertilization.

  4.4. Propagation

4.4.1. Division of Clumps (most common method)

• Period:
• Spring or early summer.
• Procedure:

1. Remove the plant from its pot and carefully separate the rhizomes with the roots.
2. Each division should have
3. at least 2–3 leaves and healthy roots
4. .
5. Replant in fresh substrate and maintain high humidity.

• Success Rate:
• High if humidity conditions are maintained.

4.4.2. Stem Cuttings

• Period:
• Spring–summer.
• Procedure:

1. Take a healthy stem with at least
2. 2 nodes
3. .
4. Place in water or a moist substrate (perlite + peat).
5. Maintain at
6. 20–25°C
7. with high humidity.

• Success Rate:
• Variable depending on the species.

4.4.3. Seed Propagation (rare for hybrids)

• Period:
• Spring.
• Procedure:

1. Sow the seeds in a moist mix (peat + sand).
2. Maintain at
3. 25–30°C
4. with high humidity.
5. Germination may take
6. several weeks
7. .

• Note:

• Rarely used in commercial cultivation (Calatheas are often propagated by division). Source: RHS - Propagating Calathea

  4.5. Pruning and General Care

• Cleaning the leaves:

• Gently wipe with a damp cloth to remove dust (Calatheas are sensitive to mineral deposits).

• Removing dead leaves:

• Cut off yellow or damaged leaves at the base.

• Repotting:

• Every

• 2–3 years

• or when the roots come out of the pot.

  5. Common Diseases and Problems

5.1. Water-Related Problems

5.2. Light-Related Problems

5.3. Pests

5.4. Fungal and Bacterial Diseases

6. Commercial Aspects

6.1. Popular Varieties and Their Characteristics

6.2. Where to Buy?

• Specialized nurseries

• (e.g., Pépinières du Val d'Erdre, Truffaut).

• Online stores:

• Plantes pour tous

• Bakker

• Amazon

• (pay attention to the quality of the plants).

• Plant markets

• (e.g., Marché aux fleurs de Paris, tropical greenhouses).

• Garden centers and hardware stores

• (e.g., Jardiland, Leroy Merlin).

  6.3. Prices and Market

• Average price:

• Between

• €20 and €120

• depending on the variety and size.

• Growing market:

• Calathea plants are becoming increasingly popular in Europe and North America, especially thanks to social media (Instagram, TikTok) which showcase their decorative foliage.

• Professional demand:

• Used in

• hotels, offices, and indoor green spaces

• for their tropical aesthetic. Source: Market Research Future - Indoor Plants Market

  7. Uses and Multifunctionality

7.1. Indoor Plant

• Decoration:

• Ideal for modern interiors, offices, and greenhouses.

• Air Purification:

• Like all plants, it contributes to the absorption of CO₂ and the humidification of the air (less effective than plants like

• Spathiphyllum

• or

• Sansevieria

• , but appreciated for its aesthetics).

  7.2. Use in Landscaping (Tropical Zones)

• Ground Cover:

• Certain species (

• Calathea lutea

• ) are used as ground cover in tropical gardens.

• Understory Plants:

• Suitable for shaded and humid areas of tropical gardens.

  7.3. Other Uses

• Fibers:

• The leaves of

• Calathea lutea

• are used to make baskets and mats in Central America.

• Traditional Medicine:

• Some communities use the leaves for their anti-inflammatory properties (usage limited and poorly documented scientifically).

  8. Sources and References

1. Wikipedia - Calathea
2. Missouri Botanical Garden - Calathea
3. Kew Royal Botanic Gardens - Calathea
4. RHS - Propagating Calathea
5. University of Florida - Calathea Pests
6. Market Research Future - Indoor Plants Market
7. Pépinières du Val d’Erdre

   9. Appendices

9.1. Maintenance Calendar

9.2. Quick Diagnostic Chart