Epidendrums - Crucifix Orchids

Epidendrum radicans

Contents

1. Top Tips
2. Location, Water, Humidity & Fertilisation
3. Dormancy Care & Annual Flowers
4. Common Issues
5. Origins, Temperature, Propagation, Repotting & Toxicity.

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Top Tips & Info

• Care Difficulty - Very Easy (second easiest Orchid behind Ludisia).
• Minimal sunlight is best for Epidendrums, as too shady locations will inhibit the chance of blooms. Provide an hour of off-peak sunlight in the spring and summer, while increasing this slightly to three hours in the dormancy period.
• Keep the soil slightly drier than other Orchids, allowing the soil's top half to dry out in between waters.
• Supplement with an Orchid-labelled fertiliser once a month, via a foliar or liquid feed.
• For a winter show of flowers, reduce the ambient temperature to around 13℃ (55℉) with fewer irrigations during this time. Scroll down to 'Dormancy Period & Annual Flowers' for further information on this.
• Repot every three years using an Orchid Bark and a slightly larger pot, during the spring. Epidendrums do best in a well-aerated potting mix, much similar to the Moth Orchid.

Location & Light - 🔸🔸

Epidendrums are best suited in a location that offers two hours of morning or evening sun, all year round. Excessively bright locations will lead to the heightened chance of dehydration and sun-scorch, as in the wild they're protected by the canopy of taller trees. 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.

Water - 🔸

While in bloom, prevent the soil from becoming dry for too long. Persistent droughts will significantly disturb the blooming process, with older flower loss 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.

Humidity - 🔸🔸

Although moderate to high humidity is ideal, their thick leaf tips enable Epidendrums to deal with dry air rather well. While the heaters are operating, introduce a pebble tray to prevent the risk of sudden flower loss when in bloom. An occasional water mist will remove the thin layer of dust from its foliage, but always keep in mind the heightened chance of botrytis or powdery mildew if situated in a dark environment.

Fertilisation - 🔸

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. Click on this link and scroll down to the 'Orchid Fertilisers' section for our recommended brands and products!

Transplanted 'Keiki's can be placed in a mixture of Orchid Bark & multipurpose compost with perlite once the roots surpass two inches. Epidendrum ibaguense. 

Dormancy Care & Annual Flowers

Epidendrum blooms are easily achieved when its winter 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 late 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℉).

Hydration

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. 

Occasional Feeds

Whilst in bloom, use a Tomato feed to provide monthly nourishment of potassium; fertilisation isn't needed until the first flower spike emerges from the base.

Reduce Everything

This one is to remind you that everything needs to be reduced - especially the temperature.

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 Epidendrums 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.

A fantastic collection of Epidendrum ibaguense (Pictured) at Adelaide's Noarlunga Orchids & Roses. 

Common Issues with Epidendrums

Root rot is key issue with Orchid cultivation. Roots will start to turn brown or mushy, and if not treated in time, it can begin to cause fungal issues. The disease is commonly caused by either moisture in between irrigations, or water-logging, usually accompanied by a dark location. Click on this link to learn about how to address this issue.

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. If you'd like to speak to ukhouseplants in regards to this issue, be sure to book a 1-to-1 video call for more detailed advice.

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.

New buds won't develop on an already-flowered stem. As soon as the blooms drop off, this will spell the end of both foliar and flora growth on that particular shaft. Wait until the new basal stems mature for another show of flowers - you'll know when it has reached maturity when no juvenile growth develop at the top.

A sudden loss of older flowers with a yellowed stalk is 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 Blight 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. Click here for more info - Common Orchid Diseases

Origins

Since Carl Linnaeus erected the genus in the 1760s, species within Epidendrum have bounced back and forth between genera. He placed most of the known epiphytic Orchids into this genus without the back-up of genetic or morphological studies. Within the next few decades, the family has been stripped apart to now only include one thousand species, down by at least a third. The genus' distribution is mostly over tropical America, with many of the species found in Colombia, Venezuela & northern Brazil. The word 'Epidendrum' can be translated from Greek to mean 'upon trees', in reference to their epiphytic nature, even though most species are considered terrestrial. 

The Distribution of Epidendrum in Green. Blue = E. radicans,  Purple = E. imbaguense,  &  Red is both.   

Temperature

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 more than two hours of 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.

Spread

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 bulbs or shafts 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.

Propagation

Via Seed, Pseudo-Bulbous Offsets & 'Keiki' (Stem Cuttings).

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) - 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.

A well-rooted 'Keiki' that was taken from a spent inflorescence stalk. Plant: Epidendrum radicans.

'Keiki' (Stem Cuttings) (Easy & Recommended) - Small offsets, or Keiki's, will develop along the mother plant's stems on various non-flowering nodes, producing a root after several months. Once the Keiki has developed an inch-long root (2cm), prune it off using a clean pair of scissors. Cut closely to the joining that connects the mother to the Keiki, while including as many roots as possible to help the plant's ability to absorb moisture. Place the bottom third of the cutting into a 7cm transparent pot with Orchid Bark, where the roots are housed, and give it a thorough water. Provide a bright indirect setting with a humidity tray, and follow the care requirements mentioned at the top of the article for its ongoing care requirements!

Flowers

Epidendrums naturally flower in the winter or spring months with large shafts baring from the centre of its stems. Most shafts can reach between 30cm to 1m; however, recent hybrids have reduced this down to below 40cm. Most flowers will be arranged in globular corymbs or panicles (with the latter pictured above). To entice the growth of 'Keiki's' when its flowers have elapsed, be sure to cut the shaft into 20cm intervals with a thick layer of sphagnum moss wrapped around its middle; scroll up to 'Propagation' for more information. The best way to tempt any Orchid into flowering is by reducing the temperature and waters & keeping it pot bound. Have a read of the 'Dormancy Period & Annual Flowers' above for further information on this.

The nickname, 'Crucifix Orchid', originates from the similarity between its labellum and a small cross. Epidendrum radicans.

Repotting

Infrequent repots will restrict its growth in trade 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 in flower) 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 a 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. Click here for a detailed step-by-step guide on transplantation, or via this link to learn about repotting with root rot.

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 Epidendrums are root rot, leaf-spot disease, rust, mosaic virus (brown or purple spots on the leaves), black rot, botrytis petal blight, powdery mildew & southern blight - click here to learn more about these issues.

Toxicity

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.

Retail Locations

You're more likely to find this genus via online stores, with E. radicans & E. ibaguense being most popular.

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