Overview
Dendrobium bigibbum Lindl., commonly known as the Cooktown Orchid, is a strikingly beautiful epiphytic orchid species found in the tropical forests and coastal plains of northern Queensland, Australia. It is one of the most popular and highly valued flowers in the country and is considered the floral emblem of Queensland.
Appearance
The plant has pseudobulbs that reach up to 60 cm in height when mature. The pseudobulbs are oval-shaped, yellow-green in color, and have a somewhat flattened appearance. Each pseudobulb produces between 2 to 6 long, narrow, strap-like leaves that are up to 15 cm in length. The flowers of Dendrobium bigibbum are the most striking feature of the plant. They are usually pink or purple in color, with a darker center, and have a delicate and pleasant fragrance.
Common Names
The Cooktown Orchid is the most common name for this species of orchid. However, it is also known as the Dancing Ladies, Bridal Veil Orchid, and Two-spiked Dendrobium due to the two spiky structures that grow from each pseudobulb.
Uses
Dendrobium bigibbum is primarily used for ornamental purposes as a cut flower or potted plant. In Australia, it is a highly valued plant that is used in horticultural shows and competitions, and it is also a popular choice for home gardeners. It is not commonly used for medicinal purposes; however, some medicinal properties have been attributed to other species of the Dendrobium genus.
Light Requirements
Dendrobium bigibbum Lindl. requires bright, filtered light to grow properly. Placing the plant near a window where it can receive indirect sunlight is ideal. Excessive exposure to direct sunlight can be harmful to the plant, while insufficient light can result in stunted growth and lack of blooming.
Temperature Requirements
This plant thrives in warm to hot temperatures, with a temperature range of 15 to 35 degree Celsius. During the day, the ideal temperature range is between 24 and 30 degree Celsius, while the temperature at night should not drop below 15 degree Celsius. Dendrobium bigibbum Lindl. can tolerate slight temperature fluctuations, but it is essential to protect the plant from extreme temperature changes.
Soil Requirements
Dendrobium bigibbum Lindl. is an epiphytic orchid species, meaning it does not grow in soil in its natural habitat. To mimic its natural environment, the plant requires a well-draining mix consisting of bark, sphagnum moss, or coconut husk. A mix with too much moisture can cause the roots to rot, while a mix with poor drainage can lead to dehydration and eventually, death of the plant.
Cultivation Methods for Dendrobium bigibbum Lindl.
Dendrobium bigibbum Lindl. is an orchid that grows best in warm and humid climates. It can be grown outdoors in areas where the temperature range is 20?C to 30?C. However, it is advisable to grow it indoors to maintain consistent temperatures and humidity levels.
The plant prefers a well-draining growing medium that provides aeration and moisture retention. A mixture of sphagnum moss, bark, and perlite is ideal. The growing medium should be moist but not water-logged to avoid root rot.
Watering Needs for Dendrobium bigibbum Lindl.
Dendrobium bigibbum Lindl. requires frequent watering during the growing season, which is from spring to fall. The plant should be watered when the top layer of the growing medium is dry. It is essential to avoid water-logging the plant, as it can lead to root rot. During the dormant season, which is in winter, watering should be reduced to prevent waterlogging.
Fertilization for Dendrobium bigibbum Lindl.
The plant requires frequent feeding during the growing season to support its growth and blooming. Fertilizer should be applied once a week, using a balanced orchid fertilizer. Specialized orchid fertilizers have a formulation that provides the right amount of nutrients to the plant. Fertilizer application should be reduced during the dormant season to avoid shocking the plant.
Pruning Dendrobium bigibbum Lindl.
Pruning is essential for maintaining the shape and size of the plant. The best time to prune is after the blooming season. Any damaged or dead leaves and stems should be removed. The plant can be divided to propagate new plants. The divisions should be made when repotting the plant, using a sterile tool to minimize the risk of infection.
Propagation of Dendrobium bigibbum Lindl.
Dendrobium bigibbum Lindl. is commonly known as the Cooktown orchid and is a popular ornamental plant. It is relatively easy to propagate and can be propagated through multiple methods.
Propagation by Division
Propagation through division is the most common method and is preferably done after the flowering period and before new growth emerges. The plant should be gently removed from its pot and gently separate the pseudobulbs with a sharp and sterile cutting tool. The separated plantlets should be planted in separate pots with a well-draining potting mix consisting of bark, perlite, and charcoal. Apply a weak dose of fertilizer to encourage growth.
Propagation by Back Bulbs
Dendrobium bigibbum Lindl. can also be propagated by back bulbs. Select healthy back bulbs from the parent plant and ensure they have sufficient roots and have at least one visible bud. Cut the back bulb from the parent plant and plant them in a well-draining potting medium with only the top visible. Back bulbs can also be placed in a small pot or container filled with course potting mix and kept in a humid and warm spot to encourage the development of new plants.
Propagation by Keikis
The propagation of keikis is another method for propagating Dendrobium bigibbum Lindl. Keikis are small plantlets that grow from the nodes on the stem of the parent plant. These plantlets can be removed when they reach a size where they have at least two leaves and compact roots. These keikis can be grown in small containers with a well-draining potting mix and kept in warm and humid conditions. Once the keikis are established, they can be replanted in larger containers.
Disease and Pest Management for Dendrobium bigibbum Lindl.
Dendrobium bigibbum Lindl. is a beautiful orchid species that can be susceptible to various diseases and pests. Here are some common diseases and pests that might affect the plant and ways to manage them.
Common Diseases
1. Leaf spot: This disease is caused by various fungi that can cause small, round spots on the leaves. To manage this disease, remove any infected leaves and reduce humidity levels. Avoid overhead watering and use a fungicide if necessary.
2. Stem rot: This disease is caused by bacteria and fungi that can cause the stem to become soft and mushy. To manage this disease, remove any infected parts and avoid over-watering. Use a fungicide if necessary, and ensure that the plant is in well-drained soil.
3. Virus: This disease can cause various symptoms such as yellowing of the leaves, stunted growth, and distorted flowers. Unfortunately, there is no treatment for virus-infected plants. Therefore, it is best to remove and discard any infected plants and avoid planting in the same area as infected plants.
Common Pests
1. Aphids: These small, pear-shaped insects can be found on the leaves and stems of the plant, sucking out the sap. To manage this pest, hose off the plant with a strong jet of water or use insecticidal soap.
2. Mealybugs: These insects look like small, cottony masses and can be found on the leaves and stems. They also suck out the sap and can weaken the plant. To manage this pest, use a cotton swab dipped in alcohol to wipe off the insects or use insecticidal soap.
3. Thrips: These tiny insects have narrow bodies and fringed wings. They can cause the flowers to become distorted and can spread viruses. To manage this pest, remove any infected flowers and use insecticidal soap.
4. Spider mites: These tiny pests can be found on the undersides of the leaves, spinning fine webs. They can cause yellowing of the leaves and can weaken the plant. To manage this pest, hose off the plant with a strong jet of water or use insecticidal soap.
In conclusion, it is essential to practice good plant hygiene, such as removing any infected parts and avoiding over-watering. Also, it is best to use natural pest management methods rather than chemical pesticides to minimize environmental impact.
