Cymbidiums - Boat Orchids
Top Tips & Info
- Care Difficulty - Moderate
- Situate in a bright, indirect location that's away from the sun or an operating radiator.
- Keep the soil evenly moist, allowing the top third to dry out in between waters.
- Avoid persistent droughts and the use of cold water, especially while it's in bloom.
- Supplement with an Orchid-labelled fertiliser once a month, via a foliar or liquid feed.
- Scroll down to 'Dormancy Period & Annual Flowers' for information about re-blooming Cymbidiums.
- Repot every three years using an Orchid Bark and a slightly larger pot, during the spring.
- Spider Mites are the most common pest that can be found on Cymbidiums, which can lead to yellowed, mottle-like foliage with stunted growth. Click on the link to learn more about eradicating them.
Location & Light
Never situate a Cymbidium in excessive sunlight due to the heightened chance of dehydration and sun-scorch. In the wild, they're protected by the tree's canopy and therefore aren't acceptable to the harsh rays. During the autumn and winter months, move the plant into a brighter location with a splash of morning sunlight. The ideal location would be within a few metres of a north or west-facing window, or in a setting that a newspaper can be read without the use of artificial lighting. Those situated in darker locations will be at risk of root rot, along with the minimal chance of another bloom.
While in flower, prevent the soil from becoming dry for too long. Persistent droughts will significantly disturb the blooming process, with sudden older flower being a big issue. Allow the top third to dry out in between hydrations, using lukewarm water if possible. The application of cold water will shock the roots and potentially lead to weak growth and a loss of flowers. Under-watering symptoms include flower loss, pale leaves, stunted growth and a gradual decline in health. Never allow the intense sun or forgetfulness to take over, as both will result in a premature flower loss and a weakened specimen. Over-watering symptoms include lower yellowing of leaves, a rapidly declining stem, flower loss and a rotten base (pseudobulbs). These issues are commonly down to either too much soil moisture, an incorrect soil medium, too little light, or foliage that has allowed to remain wet for long periods.
Dry air will cause the yellowing or browning of leaf-tips, commonly caused by the operating heaters. Place the plant on a pebble tray all year-round to increase the surrounding air moisture, avoiding the use of misters. Excess moisture in the stem's cubbyholes or flowers will entice botrytis or powdery mildew to the table.
Orchids have open stomata, meaning that fertilisation can be achieved via foliar feeds. Spray the solution onto the leaf's topside to provide the two critical ingredients for good quality blooms (nitrogen & potassium). Although typical soil-borne fertilisers will still benefit its health, only the root caps will absorb the nutrients, meaning that excess fertiliser salts may build up after a while.
Dormancy Care & Annual Flowers
Cymbidium blooms are easily achieved when its dormancy irrigations are reduced by half; those who have a cooler room without artificial light at night will also be on the upper-hand. Keep the roots pot-bound to add further stress onto the specimen, which in turn will significantly heighten the chance of flowering. Blooms will generally appear in the autumn or winter, but may occur at any given time.
The following steps should be done at the start of autumn when the plant's growth starts to slow down. Always think of ukhouseplants' acronym of SHORT when it's time for flowers...
Sunlight & Location
Be sure to provide a bright location with little to no direct sunlight. Although the winter rays won't necessarily hurt the plant, you can easily fall in the trap of sun-scorch and severe dehydration.
For the specimen to fully become seasoned, avoid the use of artificial lighting or locations that boast temperatures higher than 18℃ (64℉).
Reduce waters so that about half of the soil becomes dry. It's essential to keep them on the drier side to life, as they'll think that hard times are ahead and therefore will need to pass its genes on to the next generation.
Whilst in bloom, use a Tomato feed to provide monthly nourishment of potassium; fertilisation isn't needed until the first flower spike begins to emerge.
This one is to remind you that everything needs to be reduced - especially the temperature.
This is the most significant step; reduce the temperature down by around 5℃ compared to the summertime or place in a room that's between 12 - 15℃ (54 - 59℉). The drop in temperature should ideally last until the inflorescence finishes blooming, although it can still be transferred into the main house as long as it sits on a pebble tray. You'll be at a significant disadvantage if the ambient temperature is kept constant throughout the year, as Cymbidiums will only respond with flowers in cooled environments. Never exceed the minimum temperature as it could lead to plant death or yellowed foliage at a bare minimum.
Common Issues with Cymbidiums
Directly pinpointing yellow leaves is quite hard due to the many different issues that could be at fault. Problems include watering-related abuse, too much or too little light, and fertilisation issues.
Root rot is a common issue with specimens sat in too moist or waterlogged soil for long periods. Symptoms include rapidly yellowing leaves, stunted growth and a rotten brown base. Take the plant out of the pot and inspect health below the soil line. If the roots sport a yellow tinge, you're good to go, but if they're brown and mushy, action must be taken immediately.
Specimens that develop purple or reddened foliage are located in too intense sun. Although this isn't too much of a concern, we'd recommend reducing the amount of light slightly, so that the Orchid doesn't develop signs of sun-scorch.
A lack of flowers is caused by an insufficient dormancy period, where the temperatures are kept more or less the same over the year. Reduce the temperature by a couple of degrees over the autumn and winter months, along with fewer irrigations.
A sudden loss of older flowers with a yellowed stalkis a sign of prolonged droughts. Especially during the flowering process, near-continuous moist bark is mandatory for extended blooms; allow the roots to turn a green-greyish colour in between irrigations.
Short-lived flowers could be the product of low humidity. Place the Orchid on a humidity/pebble tray, keeping the reservoir topped up with water while the heaters are operating. Never mist the flowers due to the high risk of developing Botrytis.
Total flower loss can be caused by an array of different issues, including a change in location, too little hydration, too hot or cold temperatures or droughts and pests. While the plant is in bloom, keep the bark evenly moist to hydrate the thirsty work of producing flowers. Locations that are outside of the recommended temperature bracket (below), or have drastic fluctuations must also be kept off the cards. Alternatively, a setting that offers similar temperatures all year round can inhibit blooms. They'll respond very well if the autumn and winter months are a couple of degrees cooler than in summer. In essence, this will not only winterise the plant, but it'll also force it into a dormancy period which is a crucial ingredient for successful flowers. The final issue is pests. Although it's highly unlikely that an infestation will cause a sudden change in health, have a quick inspection for Spider Mites, Aphids and Mealybugs.
Large quantities of aerial roots that cascade over the pot shouldn't cause concern. Once the flowers have fully elapsed, take the plant out of its pot and remove any brown roots when repotting into a bigger pot. If there are a couple still above the soil, either direct them face-down into the compost or allow them to carry on cascading. Be sure to mist the aerial roots while watering the bark to ensure sufficient hydration. If they begin to split, it's the result of too little water or humidity or sun-scorch. Remove once they've fully yellowed over.
Botrytis Petal Blights are small spots or patches that'll develop on the flowers' bodies, usually caused by misting or an over-humid location with poor air circulation. Remove the infected flowers or the complete stalk with sterile utensils to put a stop the airborne disease. Improve the air circulation and move to a slightly brighter location with no direct sunlight. Be careful not to saturate the flowers from there on in, and regularly inspect to see if it has spread.
There are over a sixty species of Cymbidium, all of which originate from tropical locations in South-East Asia. Most specimens are epiphytic or lithophytic, meaning that they grow on trees or rocks, with very few growing on the jungle floor. The genus was first described by Olof Swartz in 1799, using the Ancient Greek words for "boat", 'cymba', & "little", 'idium,' in reference to the shape of the labellum.
10° - 27°C (50° - 80°F)
H1b (Hardiness Zone 12) - Can be grown outdoors during the summer in a sheltered location with temperatures above 12℃ (54℉), but is fine to remain indoors, too. If you decide to bring this plant outdoors, don't allow it to endure any direct sunlight as it may result in sun-scorch and dehydration. Regularly keep an eye out for pests, especially when re-introducing it back indoors.
Up to 1m in height & 60cm in width, with maturity being achieved in around 5 - 8 years.
Pruning & Maintenance
Remove yellow or dying leaves, and plant debris to encourage better-growing conditions. While pruning, always use clean scissors or shears to reduce the chance of bacterial and fungal diseases. Never cut through yellowed tissue as this may cause further damage in the likes of diseases or bacterial infections. Remember to make clean incisions as too-damaged wounds may shock the plant, causing weakened growth and a decline in health.
Cut and separate any rotten pseudobulbs that are located at the base of the plant. Never remove those that lack leaves but are still green and plump as they'll produce pseudo-bulbous offsets.
Via Seed & Pseudo-Bulbous Offsets.
Seed Propagation (Difficult) - Obtaining and sowing of seeds is both problematic and near-impossible without the correct equipment. Sow on a seaweed-based agar in an enclosed transparent tub on some bottom-heat (25℃, 77℉). Do not open the container until the seedlings are around two inches in height with adequate roots. Pour water into the agar to loosen it off the roots, and pot them up into 5cm (2 inches) pots with Orchid Bark. Maintain high humidity and bright indirect light to alleviate the severity of environmental shock, which can be achieved using a pebble tray. Follow the care requirements mentioned at the top.
Pseudo-Bulbous Offsets (Easy When Treating the Specimen with Respect) - It's best to divide during the spring with plantlets that are at least a third of the size of the mother plant with several developed roots. Take the plant out of its pot and place your fingers in between the two bulbs; soil may have to be removed to get a better grip. While placing your hand closely to the nodal junction, gently push the pup downwards and support the mother plant - you should hear a snap. Cautiously separate both the mother plant and pup's roots systems, keeping great empathise in keeping the roots intact and undamaged. Place the new plantlet in Orchid Bark, much similar to the original soil, and maintain the same care routines. Be sure not to use a pot that is too big as a ratio of roots-soil that leans much towards the latter will cause root rot.
Flowers can last up to two months and can bloom at any time, most commonly between the period of autumn and spring. Each spike can reach up to 50cm in height with six flowers per branch. The best way to tempt any Orchid into flowering is by reducing the temperature & keeping it pot bound; have a read of the 'Dormancy Period & Annual Flowers' above for more information...
Infrequent repots will restrict its growth for a potential bloom. They'll be under threat by the challenging environment, and as they'll potentially die (so they think), a flower shaft will be produced to pass on its genes to the next generation.
Repot every three years (& when not flowering) in the spring, using Orchid Bark and the next sized pot with adequate drainage. Don't worry if you snap the Velamen (white spongy epidermis) that covers the roots as it'll re-fuse again within the following few weeks. Hydrate the plant 24hrs before the tinkering with the roots to prevent the risk of transplant shock. For those that are situated in a darker location, add a thin layer of small grit in the pot's base to improve drainage and downplay over-watering.
Pests & Diseases
Keep an eye out for mealybugs, spider mites, scale, thrips, whitefly & root mealybugs that'll locate themselves in the cubbyholes and undersides of the leaves, except for the latter in the soil. Common diseases associated with Cymbidiums are root rot, leaf-spot disease, Cymbidium mosaic virus (brown or purple spots on the leaves), black rot, botrytis petal blight, powdery mildew & southern blight.
Not known to be poisonous by consumption of pets and humans. If high quantities are eaten, it may result in vomiting, nausea and a loss of appetite.