Cultivation

Barkeria orchids can be challenging or impossible to grow if hobbyists apply cultivation techniques that they use for other genera. Barkeria do not play by the same rules as other orchids and their dissimilar growing habits must be respected and accommodated.

Most information available online says that Barkeria plants MUST be grown mounted. Certainly growing them as epiphytes is possible for most of the species, but this should not be considered a requirement. The reason given for growing them as mounted epiphytes is that the roots of Barkeria must dry completely and must never be allowed to retain moisture. This is true, but this does not mean that Barkeria plants are incompatible with pots. We have had great success in growing the plants in plastic net pots. The open nature of the pots easily allows air to reach the roots. Net pots are ideal for growing the Uniflora and Obovata sections of the genus with thin, wiry roots. On the other hand, terracotta ceramic pots without decorative glazing are recommended for plants in the Scandens section on account of their thick, rugose roots. Many of the species in this section are lithophytic and so the rough texture of the pot allows the roots to adhere easily. Also, after the pots are watered, some of the water is absorbed by the pores of the ceramic material. This retained water will be absorbed by the roots little-by-little in a wicking action during the course of the day, and if a breeze blows over the pot it will cool the roots via evaporative heat transfer.

Potting media should be carefully selected. For plants in the Uniflora and Obovata sections a few wisps (not chunks) of long-fibered coconut husk may be all that is needed. For plants in the Scandens section expanded ceramic pellets could work if some organic matter is worked into the potting mix. These species seem to like having the tips of their roots growing in decomposing leaf litter and so they are more accommodating regarding a medium that will hold a bit more moisture at times. We prefer expanded polystyrene pellets because this medium is chemically inert, will hold plants in place, never break down and the plants just love it. The Barkeria love expanded polystyrene pellets so much that their roots will actually penetrate and grow into the polystyrene material. Since the polystyrene is hydrophobic it will not absorb water nor will the Barkeria roots adhere to the material. This makes repotting a breeze since the plant can be lifted up and the pellets removed from around the roots to be replaced by fresh pellets. The pellets only need to be replaced when algae, salts, fertilizer or pesticide residues begin to coat the pellets. The pellets made of polystyrene do not decompose which may make them unpalatable to some growers for environmental reasons. For this reason, we are experimenting with different brands of biodegradable packing peanuts with the goal of transitioning our potting media in the near future.

With few and very rare exceptions all Barkeria orchids grow on the Pacific Coast of Mexico or Central America. These areas are subject to more intense seasonal drought than comparable habitats on the Caribbean side. This means that Barkeria plants experience distinct periods of seasonal rainfall during the year that coincides with their growth. The rainy season in Mexico runs from May 15 to October 15 and plants should be watered heavily during this time. We recommend daily watering at midday to allow the plants to be completely dry by night. If plants are not completely dry by nightfall, fungal or bacterial infections can occur.

Ideally you should water with low EC water that is low in dissolved solids to prevent salt build-up on the roots and leaves. Harvested rainwater is excellent for this purpose.

During the dry season, plants should be watered once per week, but careful judgment must be used in fine-tuning the amount of water that they receive. If the sky is overcast as is common during the winter months then watering frequency should be lessened. It is a fallacy that Barkeria plants resent watering during their dormancy period. In fact, plants that are watered during their dormancy period will often retain their leaves and be much more vigorous the following growing season since there is additional surface area from the retained leaves for photosynthesis to occur. These retained leaves should be considered a bonus but they are not required for normal growth the following year. There is a prevailing idea that the plants should not be watered at all during their dormancy period in order to stress the plants so much that they are forced to drop their leaves. This is bad advice. But some species are especially prone to dropping their leaves and no amount of watering will prevent this. This is OK.

Another common misconception is that watering during a plant’s dormancy period will cause the plant to break dormancy and commence growth. In fact, fertilizing and watering have little effect on the induction of new growths in Barkeria plants so the grower can water during dormancy without any worries. Our experience indicates that growth regulation is almost entirely dependent on cues that the plant obtains from daylength. If you are growing under lights, you may have problems growing Barkeria plants because they are unaccustomed to growing in the presence of a constant photoperiod. Artificial lights should be used to supplement natural light but not completely replace it.

With few and very rare exceptions all Barkeria orchids grow on the Pacific Coast of Mexico or Central America. These areas are subject to more intense seasonal drought than comparable habitats on the Caribbean side. This means that Barkeria plants experience distinct periods of seasonal rainfall during the year that coincides with their growth. The rainy season in Mexico runs from May 15 to October 15 and plants should be watered heavily during this time. We recommend daily watering at midday to allow the plants to be completely dry by night. If plants are not completely dry by nightfall, fungal or bacterial infections can occur.

Ideally you should water with low EC water that is low in dissolved solids to prevent salt build-up on the roots and leaves. Harvested rainwater is excellent for this purpose.

During the dry season, plants should be watered once per week, but careful judgment must be used in fine-tuning the amount of water that they receive. If the sky is overcast as is common during the winter months then watering frequency should be lessened. It is a fallacy that Barkeria plants resent watering during their dormancy period. In fact, plants that are watered during their dormancy period will often retain their leaves and be much more vigorous the following growing season since there is additional surface area from the retained leaves for photosynthesis to occur. These retained leaves should be considered a bonus but they are not required for normal growth the following year. There is a prevailing idea that the plants should not be watered at all during their dormancy period in order to stress the plants so much that they are forced to drop their leaves. This is bad advice. But some species are especially prone to dropping their leaves and no amount of watering will prevent this. This is OK.

Another common misconception is that watering during a plant’s dormancy period will cause the plant to break dormancy and commence growth. In fact, fertilizing and watering have little effect on the induction of new growths in Barkeria plants so the grower can water during dormancy without any worries. Our experience indicates that growth regulation is almost entirely dependent on cues that the plant obtains from daylength. If you are growing under lights, you may have problems growing Barkeria plants because they are unaccustomed to growing in the presence of a constant photoperiod. Artificial lights should be used to supplement natural light but not completely replace it.

A general purpose, urea-free fertilizer with a N-P-K formula of 20-10-20 is recommended. Barkeria are fast growers but not heavy feeders so an application of fertilizer perhaps twice per week is more than sufficient. Since Barkeria should not be planted in an absorbent medium (see above), foliar fertilizer should be applied to leaves and exposed roots. For maximum penetration the fertilizer should be sprayed when the temperature is cool so that the leaf stomata are open. In our experience, Barkeria benefit from supplemental administration of calcium and magnesium using products labeled as “CalMag” plant nutrient additive. CalMag should not be mixed in the same solution as normal N-P-K fertilizer because mixing will cause the dissolved solids to precipitate. Instead, this should be applied once every two weeks. We also provide a high phosphate specialty fertilizer in the fall immediately before spiking commences to initiate bloom spikes, but this can be considered optional.

Barkeria plants come from tropical climates where there warm sunny days, mild winters and no freezing nights. The plants from the Obovata and Uniflora sections are native to very hot areas and enjoy blazing daytime temperatures in excess of 95F (35C) during the hottest months of the year. That said, the plants benefit from cooler temperatures at night. The Scandens section tends to be somewhat more temperate with regards to temperature requirements. These plants would prefer to be 10-15F degrees cooler during the day than the hot-growing Obovata and Uniflora sections. If several Barkeria species are grown as a mixed collection, the plants from the Scandens section can be strategically placed in areas of faster air movement as this seems to be of substantial benefit to them.

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