Plants of the genus Cassia (and its corresponding group Senna, the result of the most recent botanical revisions) constitute a diverse and fascinating set of species that adapt perfectly to both grounds as potted cropThese plants stand out for their spectacular flowering, predominantly yellow and golden hues, and their enormous ornamental value. Furthermore, some Cassias have been traditionally used in natural medicine, and many of them are surprisingly easy to grow, making them an ideal choice for all types of gardening enthusiasts.
In this article we make a complete review of the main types of Cassia and Senna that you can grow at home, explaining their botanical characteristics, origins, medicinal properties (if any), basic care, tips for growing in pots and in the garden, as well as other unique facts about each species.
Before presenting the exhaustive list of species, it is worth clarifying that, after several taxonomic revisions, a large part of the species formerly known as Cassia have been reclassified under the genus SennaHowever, both share a tribe and subtribe (Cassieae and Cassinae) and have similar cultivation requirements. Therefore, in this guide, we include species from both genera, always indicating the current botanical name and its traditional synonym.
General characteristics of Cassia and Senna
- Variety of species: There are more than 130 recognized species, and if we add those of the Senna genus, the diversity is even greater.
- Habitat: Originating mainly from tropical and subtropical regions of Central and South America, Asia and Africa.
- Increase: Most grow as small or medium-sized shrubs, although some can reach impressive tree dimensions.
- Flowering: Produce bunches of flowers Striking, almost always yellow, although some have pink or orange flowers. In many species, flowering occurs from spring to autumn.
- Sheets: Simple or compound, with several bright green leaflets, which add freshness to the garden as a whole.
- Fruit: Almost all Cassias produce legume-shaped fruits, usually hanging and brown when ripe.
Their adaptability and resilience allow them to thrive in sunny environments with well-drained soils, and many varieties tolerate both acidic and neutral or slightly alkaline soils. These qualities make them ideal for those seeking color, easy maintenance, and an exotic touch in their green space.
Basic care of Cassia in pots or gardens
If you're wondering what care Cassia and Senna require to achieve their full potential, consider these aspects:
- Light: Most species require full sun exposure, which promotes vigorous growth and abundant blooms. In very warm areas, they tolerate some semi-shade.
- Irrigation: They prefer regular watering during spring and summer, especially if potted, allowing the substrate to dry slightly between waterings. They do not tolerate waterlogging.
- Soil and substrate: For the garden, a nutrient-rich, well-drained soil is ideal. In a pot, use a lightweight universal potting mix, preferably with perlite or sand to promote drainage.
- Temperature: They love warmth. In climates with frost, it's best to grow the more delicate species in pots so they can be protected indoors during the winter.
- Pruning: Pruning is done in late winter or just before spring budding. In pots, more drastic pruning is recommended to control rapid growth and maintain the desired shape.
- Subscriber: Apply balanced fertilizer every 4-6 weeks during the growing season to promote flowering and leaf development.
These basic guidelines will ensure you have vigorous, vibrant plants, whether you choose compact species or tree-like varieties.
Main types of Cassia and Senna for growing in pots or gardens
Cassia acutifolia / Cassia angustifolia (senna alexandrina): Sen of Alexandria
This species, currently known as senna alexandrina, is native to Egypt, Africa and parts of southwest Asia. It is a evergreen shrub which rarely exceeds 2 meters in height but is usually kept below one meter in urban gardens or in pots.
- Sheets: Compound, with 4-6 pairs of leaflets.
- Flowers: Yellow, in bunches.
- Medical uses: Traditionally used as laxative y cholagogueIts leaves and fruits (pods) are used in infusions to treat constipation. Its use should be avoided in children and pregnant women, as it can cause adverse effects.
- Cultivation: It prefers light, well-drained soils and full sun exposure. It's ideal for both window boxes and large pots.
Cassia alata (senna alata)
Known as senna alata or "ringworm bush," is native to the Americas and has naturalized in many tropical regions. Its growth ranges from 1 to 4 meters, although it tends to remain compact in pots.
- Sheets: Up to 70 centimeters, composed of 7-14 bright green leaflets.
- Flowers: Clusters of yellow flowers that can reach 60 centimeters in length.
- Medical uses: The crushed leaves mixed with vegetable oil are applied to the skin to treat fungal infections such as ringworm thanks to its properties. antifungal and antiseptic.
- Cultivation: It requires full sun and rich, moist soil, although it does not tolerate excess water.
Cassia auriculata (senna auriculata)
Originating from South Asia (India and Sri Lanka), this species, now known as senna auriculata, is another shrub of great ornamental and medicinal value.
- Level: Up to 2-3 meters.
- Sheets: Paripinnate, green and pubescent.
- Flowers: Yellow, about 5 centimeters, in short bunches.
- Medical uses: Its root is used in decoctions to relieve fever, diabetes, urinary tract conditions, and as a laxative. The leaves and bark have various medicinal applications on different continents, including the treatment of rheumatism, gout, and eye diseases.
- Cultivation: It is hardy and requires sun, fertile soil, and regular watering. Ideal for gardeners interested in plants with an ethnobotanical tradition.
Cassia corymbosa (corymbosa senna)
This bush Originally from South America, it is considered one of the best options for urban gardens and terraces, as it rarely exceeds 2,5 meters and adapts perfectly to growing in pots, provided it has enough space.
- Sheets: Light green, with oblong-lanceolate leaflets.
- Flowers: Yellow, grouped in small clusters that are very attractive to pollinating insects such as bumblebees.
- Cultivation: It tolerates both direct sun and partial shade. It tolerates frequent pruning to maintain its size and shape, expanding its potential for small patios and terraces.
Cassia didymobotrya (senna didymobotrya) – Candelabra tree
popular as sen of Africa o candelabra treeThis plant can grow between 3 and 9 meters in its natural habitat, although in a pot or with regular pruning it maintains a controlled size. It is perennial, although in cold climates it can behave as a deciduous tree.
- Sheets: Compositae, they reach up to 50 centimeters, and are deep green in color.
- Flowers: Yellow clusters distinguished by their characteristic aroma, similar to that of burnt popcorn.
- Medical uses: Used in traditional African medicine to treat skin conditions, wounds, and bites. Its popularity as an ornamental plant stems from its abundant flowering and dense branches.
- Cultivation: It prefers well-drained soil and regular watering, especially during warmer periods. It's one of the hardiest Cassias, ideal for those seeking a structural presence in the garden.
Cassia fistula – Golden Shower
La Cassia fistula, popularly known as Gold rain, is native to India, Egypt, and other tropical regions of Asia. It is a deciduous tree that can grow to over 20 meters in optimal conditions, although in a garden or pot it can be kept between 6 and 12 meters tall through pruning and spacing control.
- Flowers: Yellow, in hanging clusters up to 80 centimeters, very aromatic and spectacular.
- Fruit: Cylindrical legume, appreciated in Ayurvedic medicine.
- Medical uses: The pulp of its pods has an effect laxative mild and used as an infusion or decoction. Leaf poultices help soothe bites and bruises.
- Cultivation: It requires rich soil, frequent watering, and protection from frost. It's ideal as a centerpiece in warm gardens and also adapts to large containers.
cassia grande
Call dear o brown top, is a deciduous tree native to Central America that can reach 30 meters and develop a very wide and branched canopy. It has leaves with several light green leaflets and produces clusters of flowers. rosy very showy.
- Medical uses: It is used to treat anemia, colds, urinary problems, and dermatological conditions. A latex is extracted from the root and used as a wound healing agent.
- Cultivation: It requires space, plenty of sun, and frequent watering in summer. If grown in a pot, limit its growth by pruning and choose a large pot.
Cassia javanica – Java Cassia
La Javanese Cassia It is a large deciduous tree native to Indonesia and Southeast Asia. It can grow to over 25 meters in natural conditions but remains much shorter in pots or through formative pruning.
- Sheets: Compound, up to 40 centimeters, with numerous pairs of ovate leaflets.
- Flowers: Pink, grouped in dense clusters that cover the crown in spring and summer.
- Cultivation: Ideal for warm, humid climates. It prefers fertile, well-drained soils and full sun exposure.
Cassia obovata (senna italica)
This species, known as sen of Spain o Sen of Senegal, is native to northern and eastern Africa, although it has long been cultivated in Mediterranean and southern European areas. It is a compact deciduous shrub which usually does not exceed 60 centimeters.
- Flowers: Yellow, in terminal clusters.
- Medical uses: Leaves and seeds are used as laxatives, and the young leaves can be used on burns and ulcers.
- Cultivation: Perfect for planters and small pots due to its small size, strength, and easy handling through pruning.
Cassia obtusifolia (senna obtusifolia)
Native to pantropical regions of Asia, Africa, Oceania and America, it is an annual herbaceous plant (monocarpic) that grows rapidly between 20 centimetres and 2 metres in height.
- Sheets: Glabrous, with oblanceolate leaflets and a characteristic odor.
- Flowers: Yellow, arranged in terminal clusters.
- Culinary uses: The green leaves are part of the diet in Africa (kawal) and the roasted seeds are used as a coffee substitute or as a thickener.
- Cultivation: It germinates easily and grows quickly. Ideal for those looking for a unique and useful Cassia in the kitchen.
Cassia occidentalis (Senna occidentalis)
Also known as Western Senna, it is a perennial herb from the pantropical region that grows from 40 centimeters to 1,2 meters.
- Sheets: From 11 to 25 centimeters, with a penetrating aroma.
- Flowers: Yellow and terminal, in showy clusters.
- Usage: Roasted seeds can be used as a coffee substitute.
- Cultivation: Requires full sun and well-drained soil. Ideal for pots thanks to its compact size and hardiness.
Cassia spectabilis (senna spectabilis)
La Cassia spectabilis, today known as senna spectabilis, is a deciduous shrub or tree from Central and South America, with variable heights between 2 and 15 meters.
- Sheets: Up to 40 centimeters, with 10-16 pairs of leaflets.
- Flowers: Yellow, in highly branched clusters (panicular) that cover the canopy in the warm months.
- Cultivation: Perfect as a central plant in your garden if you're looking for a tropical effect, or in a large pot with formative pruning to control its shape.
Other types of Cassia interesting for cultivation
- Cassia leptophylla: Small tree with fine leaves and clusters of yellow flowers, ideal for large pots or compact gardens due to its contained growth and spectacular flowering.
- Cassia bicapsularis: A semi-evergreen shrub with long-flowering blooms from summer to autumn. It requires rich soil and full sun.
- Cassia artemisioides: A hardy plant especially adapted to arid climates and poor soils, making it perfect for areas with long periods of drought.
Key Tips for Growing Cassia in Pots
Growing in a container is an excellent option if you have limited space, want to control the plant's growth, or live in an area with cold winters. Keep these tips in mind:
- Choose a large pot (minimum 40 liters for medium and large species), with good drainage and resistant materials.
- Lightweight universal substrate enriched with compost. Avoid clayey or compacted soils.
- Pay regularly in spring and summer with balanced fertilizer.
- Water when the substrate is dry in the first few centimeters, avoiding waterlogging.
- Provides direct sunlight for 6-8 hours a day.
- Prune annually to maintain shape and stimulate flowering, especially in fast-growing species.
- Protect it in winter If there is a risk of intense frost, move it indoors or cover it with plastic or thermal mesh.
Frequently Asked Questions About Cassia and Senna in Home Gardening
- Can all Cassia plants be grown in pots? Not all, but many species, especially those of medium and compact size (such as Cassia corymbosa, Cassia alata, and Senna italica), adapt very well to container growing. Large specimens require large pots and frequent pruning.
- Are they pest resistant? Cassia plants are generally hardy, although they can occasionally be attacked by aphids, mealybugs, and fungal diseases if there is excess moisture. Prevention depends on good drainage and regular plant monitoring.
- Can they grow indoors? It is not ideal, as they require a lot of light, but they can remain indoors in bright conditions during the winter only in very cold climates.
- When do they bloom? Most bloom in spring and summer, although some, such as Cassia corymbosa, bloom well into autumn.
- They offer color and exoticism for much of the year.
- They adapt to a wide variety of environments and climates.
- Many species present medical uses Traditional.
- Ideal for attracting pollinators such as bees and butterflies.
- In pots, they can be grown on balconies, patios and terraces.
- Require little care and are easy to maintain.
- Several Cassias, such as Cassia fistula and Senna spectabilis, are listed among the most spectacular trees in the tropics.
- Some species, such as Cassia didymobotrya, give off unique aromas (like popcorn) that are very characteristic and appreciated by botanical enthusiasts.
- Most are honey plant, which means they attract bees and other insects, benefiting local biodiversity.
- Although many Cassia plants have medicinal properties, it is essential to follow expert recommendations and not self-medicate, as some parts of the plant can be toxic in high doses.
If you're looking for a striking, hardy plant with an exotic touch for your terrace, patio, or garden, growing Cassia or Senna is a choice that will reward you with spectacular blooms and minimal maintenance. Whether for their medicinal properties, their ornamental value, or their easy adaptation to both soil and pots, the Cassia (and Senna) genus always has something to offer. Decorate your natural space with their golden clusters and discover for yourself all that these fabulous plants can bring!