Den nobile, also known as Dendrobium Noble Rock Orchids, are epiphytes or lithophytes that grow on the branches of trees in the wild or on mossy rocks. Dendrobiums belong to the lush green tropical regions of Southeast Asia.
They prefer warm and bright environments but thrive in diverse climates, like cold mountains and warm wetlands. They have fragrant, colorful flowers and grow in groups from a cane-like pseudobulb.
The plants are typically bushier than other orchid varieties with pendulous branches. Moreover, Dendrobiums purify the air by removing toxins like xylene, which is a potent carcinogen. These are deciduous, so don’t panic if they lose some leaves. Proper care is must for Dendrobium to thrive!
Table of Contents
A Quick Glance
| Scientific Name | Dendrobium spp. |
| Common Name | Dendrobium orchid |
| Plant Type | Perennial |
| Family | Orchidaceae |
| Mature size | 6-48 inch tall, |
| Width | 6-48 inch wide |
| Flower Color | White, pink, purple, orange |
| Foliage Color | Bright green leathery |
| Season Features | Bloom in Spring, Summer, Fall, |
| Native area | Asia |
| Soil Type | Well-drained, moist |
| Soil pH | Acidic (5.5- 6.5) |
| Hardiness zone | 9-11 (USDA) |
| Sun Exposure | Bright light, 2000-4000 FC |
| Water requirements | Vary with climate regions, 2-3 times a month in winter, 1-3 times a week in summer |
| Humidity | 65%-75% |
| Temperature | 70-80 F° at day, 60 F° at night |
| Fertilizer | Weekly during active growth |
| Propagation | Division pseudobulbs/Keisis/ |
| Toxicity | Not toxic to pets |
Light Requirements
An indoor bright area with lots of sunlight is an ideal spot for Dendrobium Nobile. Place them at least 3 feet away from the south-facing window. Generally, it is fine to grow them outdoors in summer but under partial shade.
Using a light meter, you can adjust ample light exposure to a specific area. Dendrobium prefer high light, and 2000-4000 foot candles of light are excellent for them. LED, artificial growing lights are also a nice option if your house orientation does not get enough light for the orchids.
When growing orchids in growing light, do not place them near the growth lights, and suddenly expose them to higher light intensity. Gradually increase the light and turn it off at night.
Place the D. nobile for two hours in the sun in the morning and evening is enough for optimal growth. If Dendrobium is not getting sufficient light, it results in lots of keikis formation, which drains energy from the mother plant. Also, watch for dropping and darker leaves that indicate they need more sun.
Temperature
Dendrobiums prefer warm temperatures, and special care should be given to them during cold drafts. Bring them indoors in winter and keep the daytime temperature 75°-80° F and the nighttime temperature 50 F°.
In summer, maintain the temperatures between 72°-82° F with slightly chilly nights of temperature 66 F°. Spring and summer are the active growth period, so I advise you to adjust the temperature well for a lush growth. The right conditions also promote flower bud formation.
Humidity
Being a native to Southeast Asia, Nobile lives at moderate elevations. They are used to monsoon rains in summer and little to no rain in winter. So they enjoy slightly drenched conditions with high humidity. Keep 80% humidity in summers and 60% in winters with good air movement. Remember, 50% humidity is a must for the overall health of Dendrobium Nobile.
Orchid growers should invest in a humidifier and hygrometer to maintain adequate humidity and prevent pathogenic growth.
Watering Needs
If the temperature gets pretty harsh during summer, and the potting get dry, give plenty of water in summer and spring every six to seven days. Then let the water drain out.
Generally, watering needs to increase with the temperature rise. However, if the dendrobium has at least 4 new growing canes, is in full bloom, or has spikes, it needs to be watered 3 times a week.
A general rule of watering is to stick your finger in the pot and if the medium feels dry, water it. If it’s wet, wait until dryness. Keep the soil slightly moist, especially when they are in active bloom, but not soggy. Dendrobium Nobile likes to dry out between waterings.
Reduce watering in fall and winter because Nobile is not in a growth cycle. Start the watering schedule again when you observe new growth on the plant. If you are growing D. Nobile in the sphagnum moss waterless, chunky bark, charcoal, and pumice growing medium needs 1-2 times watering in a week.
Salts and impurities may build up in the pot. So, I recommend using only rainwater, reverse osmosis water, or distilled water for watering. Avoid using cold water to prevent shock to the roots and loss of flowers.
Do not let the water sit on the leaves, as it causes leaf spotting or promotes fungal diseases. To prevent this, place the plants in front of the fan for a few hours. It will dry excessive water on the leaves and improve air circulation.
Soil and Potting Mix
The potting mix of Dendrobium Nobile comprises organic materials and should be well-draining and well-aerated. You can use a regular potting mix, which is readily available, or easily make your own potting mix with coarse materials such as bark, charcoal, and sphagnum moss. The substrate ensures moisture retention and prevents waterlogging.
Dendrobium Nobile doesn’t have an extended root system. So, they thrive well in relatively small pots and likely root-bound, but avoid compacted and dense soil. I believe growing them in clay pots is best because for excellent drainage. Moreover, it’s feasible to repot them by simply breaking the pot, which saves time and effort.
How to Fertilize Dendrobium Nobile?
A diluted liquid orchid fertilizer is recommended during active growth (summer and spring). Some orchid growers prefer to fertilize the D. nobile every time they water it, but typically every 7 to 9 days is enough. Flush the plant monthly to avoid mineral buildup in the soil.
Make sure you reduce the fertilizer to half in winter, as the plants are almost dormant, so fertilizing is unnecessary. Besides, it can promote keikis formation in the mother plant.
You can adjust fertilizer regimes as per your climatic conditions. Always follow the label instructions and manufacturer’s guidelines before using any fertilizer.
Flowering
Flowers of den nobile vary in shape and color. Some are pink, purple, orange, yellow, or white with dark lips. A delicate fragrance makes the flowers even more special. The flowers may last over 6-8 weeks or are ephemeral.
Dendrobium Nobile flowers only last long when you provide the right conditions, such as light, humidity, water, and fertilizer, during the growing season.
Also, move the plant to a cool and dry location instead of in scorching sunlight when in bloom. If your D. nobile is not flowering, increase the light, and it will promote blooming in the orchids. All these factors are solely responsible for orchids to generate the energy needed for blooming.
Post Flowering Care
After the flowering season, the plant may look irregular in shape, so cut the stems back to the cane. New blooms will emerge from previous as well as other canes.
Repotting
Repot den nobile orchids after 2-3 years when the plant outgrows and the potting mix is damaged. The pot should be spacious enough to hold two to three new canes per year so the orchid can adjust easily.
- Choose a new pot 2 inches larger than the original pot and fill it with fresh medium.
- Remove the orchid and clear the extra substrate from the root ball.
- Carefully place the plant in the center and even out the potting mix.
- Care for it as per usual.
Dendrobiums are not very fond of repotting, so repot only when you observe new canes growing because older roots do not like to be disturbed. I advise repotting during the growth cycle (when not in bloom) so the plant can manage repotting stress well.
Propagation
Propagation can be done by division, seed, stem cutting, or keikis. Seed germination takes about 3 months. It is difficult and needs lots of care. Success rates are higher with division and keikis.
Before propagating the plant, make sure the Dendrobium has at least four healthy canes full of leaves. You can easily divide them by following the steps:
- Gently grab the base of the canes and wiggle them until they separate. Each new cane should have at least 3 canes. Carefully loosen up some roots for new divisions.
- If necessary, use a sterilized pruner and cut the rhizomes into segments in such a way that each one has at least four pseudobulbs.
- Remove the old substrate from the root ball and separate dead and brown pseudobulbs from each segment.
- Take a new pot around 8 cm and fill it with a fresh potting mix.
- Place each segment in the potting mix and only mist the water to moisten the soil until you observe new growth.
- Now, care for it as you care for a mature D. nobile.
Old canes also produce keikis, which are small offsets on mother plants. When these are about 2 inches long, cut them and simply put them in sphagnum moss or orchid bark until you observe new growth. Then transform it into a suitable potting mix and care for it as per the routine.
It’s a standard protocol to sterilize all tools and pots before repotting and propagation for the prevention of diseases and pests. You can use alcoholic wipes or a butane torch for sterilization.
Pruning and Maintenance
Den nobile orchids do not need pruning very often. They grow one to two canes per year. It’s normal if they get heavy at the top. Moreover, the top of the cane is heavy with a thin base, so they might need support. Staking is a popular way to grow or else they will fall over.
Their canes do not get damaged even if they fall on each other. You should arrange the canes in an alternative way to make the overall shape of the plant pleasing.
After the blooming period, they require a little trimming, so cut the dried flowers as well as remove them from where they join the stem, but do not remove the cane. Also, remove plant debris and often clean the pot to prevent pests.
Common Issues and Treatment
- Overwatering results in wilting leaves and mushy roots due to root rot, ultimately resulting in plant death.
- Underwatering signs include flower loss, pale leaves, and stunted growth.
- Yellow, Dry, and Brown leaves can be caused by multiple reasons, such as direct sunlight exposure, low humidity, over-fertilizing, or mineral buildup in the soil.
- The lack of flowers in den nobile are due to temperature changes throughout the year. Reduce 5°-10° from the normal temperature in autumn and winter. A cooler and drier rest period (dormancy) is crucial for blooming. Other factors responsible for short-term flowering are low humidity and dry air. Excessive use of heaters in winter dries the local air and use a humidifier in winter.
Some deciduous species may shed leaves, so these spots may be a part of their natural cycle. Incorrect soil media, too much moisture, and too little or too much light are the culprits behind the above issues. Adjusting the conditions will aid the plant to grow happily.
Pests and Diseases
Some common pests of Dendrobium Nobile are Mealybugs and thrips. Carefully inspect the plant often, as these bugs hide well under the area where leaves meet the cane.
- Thrips are tiny, winged insects that cause severe damage to Dendrobium leaves and flowers. Signs of thrips on orchids are silver patches, heavily-infested leaves turn brownish silver, and flower edges turn brown.
- Mealybugs are also attracted to den nobile. Signs of infestations are cottony wool substance on the canes, honeydew residue, and stunted growth.
Small pest infestations can be treated with organic and homemade pesticides, 1:1 of water and alcohol, and a few drops of mild soap. Spray every few days until you observe a difference. You can also physically remove the pests. If the plants are highly infested, use chemical pesticides and discard the damaged part.
- Leaf spot, black rot, Giardia, anthracnose, botrytis petal blight, and collar rot are the most common orchid diseases caused by viruses or bacteria. Typical signs of any of these diseases are black, brown leaf spots, foul odor, the formation of liquid-filled lesions, and premature falling of leaves.
Bacterial and fungal disease is generally caused by high humidity, waterlogging, poor ventilation, and the use of contaminated tools. Prevention of pests and diseases is easier than treatment. Isolate the plant when you first see any pest or disease signs on the orchid.
Follow good hygiene practices, use gloves and sterilize tools before directly contacting the plant and pots, and wipe the leaves with botanical wipes to clean leaves and maintain their shininess.
FAQs
Is Dendrobium nobile indoor or outdoor plants?
Dendrobiums nobile are typically considered indoor plants as they cannot endure cold drafts and direct sunlight. However, you can place them outdoors in summer with a shade cloth, in a conservatory, or in the greenhouse.
Indoors, they can be placed at 3 3-foot distance from the south-facing window. Whatever location you choose, keep the temperature range between 70 to 80 F° and reduce 5°-10° at night.
How many times a year does Dendrobium bloom?
Dendrobium Nobile or Rock Noble orchid blooms twice a year in spring or late fall. However, the blooming period may vary with different varieties. The flowers last 6-8 weeks, and each cane produces more than 50 flowers.
What do you do with Dendrobium nobile after flowering?
After the flowering period of Dendrobium Nobile, carefully trim flower spikes where they meet the cane, but do not cut the canes. New flowers emerge from the older canes and also from new ones.
Is Dendrobium nobile rare?
Dendrobium Nobile is a widespread ornamental orchid, therefore, it is not considered rare.
Is Dendrobium nobile toxic to dogs?
No, Dendrobium nobile is not toxic to dogs and any other pets. However, eating plant may cause an upset stomach. So, keep them away from your orchids.
Do Dendrobium orchids like full sun?
Yes, Dendrobiums are fond of bright light but with a shade above them. Exposing them to bright but direct light results in leaf scorching and foliage damage.
Do Dendrobium orchids like to be root-bound?
Yes, Dendrobiums like to be root-bound because they don’t have an extended root system. It makes them easy to grow in small pots.
What is the lifespan of a Dendrobium nobile?
The average lifespan of a plant depends on many factors, including species, environment, and the care it receives. Orchids have a higher life span than the majority of houseplants, and if rightly cared for, Dendrobiums can live for decades. The typical lifespan of a Dendrobium Nobile is 15-20 years.
Final Thoughts
The Dendrobium Nobile orchid, aka Noble Rock Orchid, is popular for its graceful canes and fragrant blooms. These vibrant flowers bloom twice a year with proper care, such as bright indirect light, moist soil, and warm temperatures.
Check high humidity and proper dormancy or rest for the growth. Mimick its natural environment, and you can witness their beauty for up to 20 years. Watch out for pests and diseases as they always find a way to invade. Happy Planting!
