Description of Cymbidium giganteum (L.f.) Sw.
Cymbidium giganteum (L.f.) Sw. is an epiphytic or lithophytic plant that belongs to the family of Orchidaceae. It is commonly known as the giant orchid or the king orchid and is native to the Himalayas, India, and Southeast Asia. The species name 'giganteum' refers to the large size of the plant's flowers and pseudobulbs.
General Appearance
Cymbidium giganteum is a large-sized orchid with pseudobulbs that are 60-90 cm in height and 6-8 cm wide. It has strap-shaped leaves that can reach up to 60 cm in length and 4-5 cm in width. The plant produces flower spikes that can grow up to 1 meter in length, bearing multiple large and showy flowers. The flowers are 10-13 cm wide, with sepals and petals that vary in color from greenish-yellow to brownish-red, and a lip that is white to cream-colored with purple markings.
Uses
Cymbidium giganteum has ornamental value and is often grown as a houseplant or for cut flowers. In traditional medicine, the plant has been used for various medicinal purposes, such as the treatment of wounds, fever, and respiratory infections.
Moreover, the plant is also used for commercial purposes due to the presence of bioactive compounds. The bark, leaves, and pseudobulbs of Cymbidium giganteum contain alkaloids, flavonoids, and phenolic compounds that possess anti-inflammatory, antioxidant, and anticancer properties.
In conclusion, Cymbidium giganteum is a stunning and useful plant that has found a place in medicine and in the horticultural industry.
Light Requirements
Cymbidium giganteum requires bright, indirect light. Too much direct sunlight can damage the leaves and flowers. While it prefers brightness, it can tolerate some shade as well. Ideally, it should be placed near a south or east-facing window with a sheer curtain to filter the intense sunlight.
Temperature Requirements
This plant prefers moderate to warm temperatures with a temperature range of 18 °C to 24 °C (65 °F to 75 °F) during the day and 12 °C to 15 °C (55 °F to 60 °F) at night. In winter, the plant should be kept at a slightly cooler temperature, between 10 °C to 12 °C (50 °F to 55 °F). It can tolerate occasional fluctuations in temperature, but extreme temperature changes can lead to damage or death of the plant.
Soil Requirements
Cymbidium giganteum requires a well-draining potting mix that is slightly acidic, with a pH range between 5.5 and 6.5. A mix of fir bark, sphagnum moss, and perlite is usually recommended. The potting mix should be able to retain moisture, but not become waterlogged, as this can lead to root rot. It is also important to repot the plant every two to three years to prevent the potting mix from breaking down and becoming too compact.
Cultivation Methods
Cymbidium giganteum is a terrestrial or epiphytic orchid that can be grown both in pots and in the ground. In pots, a well-draining orchid mix composed of bark, perlite, and peat moss will suffice. For in-ground cultivation, the planting area should have well-draining soil or be elevated to avoid waterlogging and root rot.
It prefers a partially shaded spot that receives dappled sunlight throughout the day. Areas with temperatures between 15-25°C with high humidity are ideal for growth. It can also tolerate brief temperature drops to around 5-10°C.
Watering Needs
Cymbidium giganteum requires regular watering, but it's essential to avoid overwatering. Orchids should be watered when the potting medium begins to dry out, typically about once a week. Overwatering can cause root rot and other health issues.
When watering, use room-temperature water and avoid getting water on the foliage or flowers. It can cause damage and induce diseases. Ensure that the drainage holes in the pot are not clogged, and the excess water is drained out.
Fertilization
Cymbidium giganteum orchids can be fed with balanced fertilizer once every two weeks during the growing season. It should be applied when watering, and the dose should be diluted to half-strength.
Avoid feeding the plant when the potting medium is dry, as it can cause root burn. During the winter, when the plant is dormant, suspend fertilization until spring when new growth begins.
Pruning
Cymbidium giganteum usually requires minimal pruning. Dead or yellowing leaves and spent flower stems should be removed promptly. The flowers usually stay on the plant for several weeks, but once they wilt, cut the stem above a node or a leaf that maintains the plant's shape.
If the plant becomes too large or overcrowded, divide it during the dormant season. Care should be taken to avoid damaging the roots or disturbing the orchid's base. Divisions should be repotted in fresh, well-drained orchid mix.
Propagation of Cymbidium giganteum (L.f.) Sw.
Cymbidium giganteum can be propagated through various methods such as division, back bulbs, keiki, and tissue culture.
Division
Division is the most common method used for propagation of Cymbidium giganteum. This involves dividing the clump of pseudobulbs into smaller sections with at least three healthy pseudobulbs in each section. The divided sections are then replanted in a suitable growing medium.
Back bulbs
Back bulbs can also be used for propagation. The back bulbs are the small dormant bulbs that develop at the base of the parent pseudobulbs. These can be separated from the main plant and grown into new plants.
Keiki
Keiki is a Hawaiian term used to describe a baby plant that grows on the stem or base of the parent plant. The keiki can be separated from the parent plant and grown in a suitable growing medium.
Tissue culture
Tissue culture is a laboratory method of propagation that involves taking a small piece of tissue from the parent plant and growing it in sterile conditions on a nutrient medium. This method can result in a large number of plants being produced in a short amount of time, but it requires specialized equipment and expertise.
Disease Management for Cymbidium giganteum
Like any other plant, Cymbidium giganteum is susceptible to diseases that can affect its health and growth. Here are some common diseases that may affect the plant and ways to manage them:
- Bacterial Soft Rot: This disease is caused by a bacterium and can be identified by the soft and mushy appearance of the plant tissues. To manage this disease, it is recommended to remove the affected plant parts and apply a copper-based fungicide to prevent the spread of the bacteria.
- Anthracnose: This disease is caused by a fungus and can be identified by the presence of brown spots on the leaves and pseudobulbs. To manage this disease, remove the affected plant parts and apply a fungicide specifically designed to treat anthracnose.
- Black Rot: This disease is caused by a fungus and can be identified by the blackening of tissues on the plant. To manage this disease, remove the affected plant parts and apply a fungicide specifically designed to treat black rot.
Pest Management for Cymbidium giganteum
Like diseases, pests can also affect the health and growth of Cymbidium giganteum. Here are some common pests that may affect the plant and ways to manage them:
- Thrips: These tiny insects can cause damage by sucking the sap from the plant tissues and can be identified by the silver or white patches on the leaves. To manage thrips, apply an insecticide specifically designed to treat them.
- Mealybugs: These pests can also cause damage by sucking sap from the plant tissues and can be identified by the white, cottony masses they leave behind. To manage mealybugs, remove them manually if possible or apply an insecticide specifically designed to treat them.
- Spider Mites: These pests can cause damage by sucking the sap from the plant tissues and can be identified by the fine webbing they leave behind. To manage spider mites, apply an insecticide or use a strong stream of water to wash them off the plant.
