How to Care for Dendrobium Kingianum
Dendrobium kingianum is a popular species of orchid that originated from eastern Australia. It is also known as pink rock orchid, as it is often found growing on rocks. Other names for this orchid are Thelychiton kingianus and Captain King’s dendrobium. Most gardeners grow pink rock orchids for their attractive flowers that emerge on a three-to-six-inch-long raceme.
If you are curious to learn more about the care requirements for Dendrobium kingianum, this article will provide you with everything you need to know to grow this beautiful orchid.
Dendrobium kingianum care tips
Pink rock orchids can grow and flower vigorously with a bit of care and attention, particularly during the warmer months. Follow the tips discussed below to successfully grow your Dendrobium kingianum:
1. Sunlight requirements
As with other orchids, Dendrobium kingianum flourishes in areas with access to bright sunlight. These ornamentals can also tolerate low lighting, but you might not see them bloom in such conditions. It is highly recommended to plant your pink rock orchids in a garden facing east, west, or south, as these directions tend to have the best sunlight exposure.
One thing to keep in mind, though, is that the afternoon sunlight can be a bit too harsh for these orchids. So, if you live in an area with a hot climate, consider using a shade cloth to protect your plants from such intense heat.
2. Ideal temperature and humidity
Dendrobium kingianum is comfortable in temperatures between 40 and 85 degrees Fahrenheit. These plants are quite tough, however, and have been known to withstand temperatures up to 104 degrees Fahrenheit.
During the winter season, make sure that your orchids are not exposed to freezing temperatures below 40 degrees Fahrenheit. Remember that the correct temperature is critical for their growth, and abrupt temperature changes can be very stressful. Consider raising the temperature gradually after the cold weather, especially if they have any flower spikes developing.
As for humidity, pink rock orchids happily thrive in an environment with 50 percent humidity. They can tolerate low humidity too, but you might not see their best growth and blooming under those conditions.
Fortunately, there are many simple methods that can help you improve the humidity in your growing area, one of which is misting. A word of warning, though – you should never mist your plants at night. Damp environments can promote fungal growth and cause unwanted rotting of the leaves and stems. Hence, you should only mist in the morning so that your plants have the entire day for their foliage to dry.
Another tip to raise the humidity is by using a humidifier. This is by far the most efficient and safest way to manage your indoor humidity. Most plants thrive in humidity of 50 to 70 percent, and a humidifier can easily help you reach this level.
3. Potting mix
Generally, almost any orchid potting mix should suit your Dendrobium kingianum. Several growers also swear by the amazing results of mixing bark and perlite or charcoal and bark, so you might also try one of these.
Dendrobium kingianum is considered an epiphyte or lithophyte. This simply means that these orchids, in their native habitat, grow on rocks or on another plant. So, instead of having their roots buried in the soil as other ornamentals do, they will be happier when grown in a well-draining medium with plentiful pockets of air.
4. Watering needs
Water plays an important role in the health and vigorous flowering of your orchids. Ideally, your Dendrobium kingianum should be watered once or twice a week from spring to summer, but this might vary depending on your local climate. Check the potting mix regularly and do not let it get too dry. Increase your watering as needed, particularly during hot spells.
When watering, make sure the excess water is able to drain thoroughly from the pot. And, for the best results, use rainwater to water your plants. Rainwater is preferable because it is low in minerals and treatment chemicals. Additionally, it is a good source of nitrogen and is slightly acidic, making it a healthier choice to nurture your orchid garden.
During wintertime, most plants become less active and it is therefore extremely important to reduce your watering to avoid root rot. Also water earlier in the day so that the foliage has plenty of sunlight hours to dry.
5. Repotting
Pink rock orchids are generally happier when left in a rootbound state. Hence, these plants do not necessarily need frequent repotting, unless the canes no longer have enough space and are about to burst from their containers.
Although your Dendrobium kingianum does not have a large root system, it might benefit from being repotted every one to two years. However, if the growing medium becomes too soggy, consider repotting it sooner to save it from root rot and other fungal diseases.
To repot your orchid, carefully untangle the roots and remove the soil debris before transferring it to a new, bigger pot. Make sure that the new container is well-draining and provides plenty of space to accommodate the roots.
6. Fertilizer
To give your orchids a boost, it is recommended to use a fertilizer rich in phosphorus if you want to encourage flowering. Avoid fertilizers high in nitrogen, as these will promote the development of foliage and keikis instead of flowers.
For fully-established pink rock orchids, using a slow-release fertilizer would be more beneficial for a continuous nutrient supply without burning the roots. Feed your orchids during the growing seasons but avoid fertilizing during the colder months. Allowing your plants a resting period over winter will give them a head start for the next flowering season.
Dendrobium kingianum keikis and propagation
Keikis are the babies of an orchid plant. If you are planning to propagate your Dendrobium kingianum, then having a keiki would be desirable. Keep in mind, though, that the production of this baby orchid will likely be at the cost of the blooms, since the mother plant will have to focus its energy on nurturing the keiki.
Additionally, the development of a keiki could sometimes mean the plant is in distress or dying. So, it all depends on your priorities – if you want your orchids to bloom, you might need to remove the keikis. You should also assess the condition of your plants to ensure that the keiki is a product of a healthy plant and not a dying plant.
To propagate your Dendrobium kingianum, the first step is to nurture the keiki until it grows about three or four roots and a few leaves. Keikis usually take about eight months to a year to grow roots, so patience is key! Sometimes, they might even produce leaves and flowers despite not having roots, and this is normal.
Once your keiki has grown its roots, it is time to separate the plantlet from the parent orchid. Carefully cut the keiki from the mother plant, leaving about one to two inches above and below the keiki’s node. Then plant your keiki in well-draining potting mix that contains bark, perlite, or charcoal. Remember not to place your baby orchids in areas with full and direct sunlight, as you want to protect their leaves from irreversible sun damage.
How big does Dendrobium kingianum get?
Dendrobium kingianum usually grows between six to 12 inches in size and is sometimes considered a weed in the orchid world due to its vigorous growth habit. The size of its flowers can vary between 0.6 to 1.6 inches, and the leaves reach one to four inches long and one inch wide.
Is Dendrobium kingianum fragrant?
Although the flowers of this Dendrobium species vary slightly in shade between pink and purple, they all share a delightful fragrance. The smell of the blooms is comparable to that of lilac, hyacinth, or honey. Unfortunately, the blooms do not last very long but the good news is that Dendrobium kingianum is a perennial so you can expect the plant to flower year after year.
How do you make Dendrobium kingianum bloom?
One thing that frustrates many newbie growers is that they cannot make their Dendrobium kingianum bloom.
As with all other orchid species, pink rock orchids take time to produce flowers – approximately a year or two. If you do not see any flowers emerging from the stalk, it might be too early to expect blooms. Wait patiently and nurture your plants as advised, and all your hard work will hopefully be rewarded in the next growing season.
Conclusion
As with other orchid species, the care requirements for Dendrobium kingianum include proper sunlight, a well-draining and airy potting mix, correct watering, appropriate temperature and humidity levels, and the odd boost of fertilizer. Keep in mind that these plants might not show their lovely blooms in their first year of growth. But, with your patience and proper nurturing, your pink rock orchids are sure to reciprocate with abundant flowers when the time is right!
Image: istockphoto.com / weisschr