Orchid Culture Techniques

Orchid Culture – An overview of the different orchid growing techniques.

Just like human society that developed a wide array of cultures and technology based on their history and environmental influences, the different orchid genera also have evolved growth mechanisms that allowed them to thrive in their native habitats. From the way their roots cling to their preferred substrate, to the way they have designed their flowers for optimum attraction of their target pollinators; orchids have found a way to maximize their survivability in their native habitat.

If money was not an issue, then most would agree that the best way to grow orchids will be to replicate their native habitats. One can only imagine the cost of building a large climate controlled enclosure that can house not only the orchids but their host flora as well.
Commercial growers have to some extent come close to this orchid utopia. But instead of replicating the native growing environment, they decided that it is more practical to just replicate the growing conditions found in those environments.
They have developed computers that control the temperature, moisture, sunlight, etc that are vital for the best growth of their plants.

But just like the rest of the world, we orchid hobbyists are not so endowed with such wealth that we can plunk down into building such a biosphere.
But such technicalities will never stop us from trying, right?

From the windowsill grower, to the greenhouse grower, and everyone in between, we eventually hone our understanding of our own growing environment and do our best to select plants that have an affinity to that environment. In time, we learn what genera will thrive with minimal intervention of environmental factors such as light, humidity and temperature, and also learn what genera should be avoided if we are not prepared to challenge Mother Nature herself.

However, climatic conditions are only part of the overall knowledge that the orchid grower must learn. There are several other factors that, if learned, will allow the grower greater flexibility in selecting orchid genera that they can grow in their own environments.

In this living article, I will attempt (with your help) to document the different orchid growing culture adopted by hobbyists to provide the best growing conditions for their plants.
This is only intended as a primer for the various orchid cultures. If you wish to learn more detailed information about the specific culture, then I recommend independent research.

For consistency, I will follow a specific format for listing and describing the information about the different orchid cultures.
• Culture/Method (In bold text)
• Target parameters
• Target environment
• Brief description/explanation.
• Known issues


In situ – native habitat
• Target parameters – varied
• Target environment – varied
• Explanation: Orchids growing in their native habitat require no human intervention in order to grow and reproduce. They have evolved to fit that environment and most likely existed there longer than man.
• Known issues: Habitat loss due to human encroachment is the most significant threat to these orchids.


Mounted
• Target parameters: Very fast drying time, Excellent root ventilation, No root restrictions.
• Target environment: Moderate/High Humidity, Frequent watering.
• Explanation: Mounting an orchid to a host (living or otherwise) most closely replicates an epiphytic orchid’s natural growing method. There are no restrictions to the root growth, and the roots do not drown in too much water as there is no pot to contain the water. This method is appropriate if the growing area has sufficient humidity to keep the plant hydrated in between watering.
For the person who absolutely loves to water, mounted orchids are the best option as they will never drown.
• Known issues: Mounted plants tend to dry up very fast unless there is adequate humidity in the growing area.


Pot culture – growing in pots
• Target parameters: Moisture retention, Root control
• Target environment: Low/Moderate humidity, infrequent watering.
• Explanation: Growing in pots is no doubt the most popular culture adopted by orchid growers. With the exception of some very specific orchids, almost all orchids can be grown in pots. The variety of pot material from plastics to clay, in combination with a dizzying array of substrate material within easy reach of the hobbyist, makes this a crowd favorite. A grower can create the “perfect potting mix” that will retain moisture for as long or as short period that works best for their orchids, as well as provide the right amount of ventilation for the roots.
• Known issues: Repot… Repot… and Repot.


Basket culture
• Target parameters: Faster drying time compared to pots, Minimal root restrictions, and excellent root ventilation.
• Target environment: Moderate/High Humidity, Frequent watering.
• Explanation: A middle ground between the mounted and potted orchid advocates, this culture allows the orchid to be “inside a container” yet still provides the excellent root ventilation and freedom offered by mounting.
The grower also has several selections of how they want to grow orchids in a basket; in a wood basket with orchid mix, in a basket with pure sphagnum moss, in an empty basket, etc. Just like the pot culture, basket culture allows the grower great flexibility in how they want their baskets to perform.
• Known issues: Once the roots take hold of the basket, it will be impossible to remove the plant. The only feasible choice is to place the entire basket into a bigger basket.


Floaters – Hang Loose!
• Target parameters: Very fast drying time, Excellent root ventilation.
• Target environment: Moderate/High Humidity, Frequent watering.
• Explanation: Certain orchids, like Vandas, seem to prefer to just let their roots hang down without the aid of a container or a potting substrate. Under proper conditions, their vast root network has evolved to absorb as much moisture as they can and no longer have the need for a potting substrate to retain moisture for them.
A variation of this is called “vase culture” where the orchid roots are grown inside an empty vase. The humidity inside the vase is higher than outside and provides a humid growing environment for the roots.
• Known issues: Most plants grown like this are usually hung from several feet high, and the root system makes it impossible to place on top of anything.


Semi-Hydroponic culture – Yes, those small red pellets.
• Target parameters: Constant moisture access, Very good root ventilation.
• Target environment: Low humidity, areas where traditional watering poses a significant challenge (indoors where water splashes are avoided, etc)
• Explanation: In recent years, the semi-hydroponic (or S/H) culture has gained popularity and the fan base continues to grow. This method utilizes lightweight expanded pellets usually made of clay, and a water reservoir in the bottom. When these pellets touch each other, the water from the bottom wicks up on the pellets’ surface and then passed on upwards to the adjacent pellets. This creates a root zone that is rich in both moisture and air that provides the plant a consistent supply of air and water.
• Known issues: Most orchids will need to go through a transition period if they are moved from a traditional potting culture into semi-hydroponic. This is because the roots will need to fine tune their physiology to adapt to the constant exposure to moisture. A healthy orchid will undergo this transition without incident.


Aeroponic culture – Orchids in Space!
• Target parameters: Constant moisture access, Constant nutrient access.
• Target environment: tech-savvy growers, varied.
• Explanation: Where Semi-Hydroponics is considered a “passive”approach, allowing natural capillary action, evaporation and gravity to deliver the water and nutrients to the plant, Aeroponics takes a direct, active approach. The plant’s roots are suspended in air and are given a fine spray of a solution that is rich in oxygen and nutrients. This nutrient spray is tuned for optimal uptake by the roots and is reported to produce better yield in crops.
• Known issues: Closed loop system required to spray and recirculate the nutrient solution.


Water culture – roots overboard!
• Target parameters : Constant water access
• Target environment: varied, very dry conditions
• Explanation: This is somewhat taking semi-hydroponic culture to the extreme. Some orchids can be grown in water culture, though the selection of known water-compatible orchids is very short due to the fact that not many people are willing to try it, thus the knowledge base is not that solid. In this culture, the plant is placed on top of a water container and the roots are allowed to grow into the water. The roots then adapt to growing under water and extract oxygen from the water that it is exposed to. Most wild epiphytic orchids do not naturally grow roots in water – unless their host tree somehow fell into the river. Although there are certain phragmepedium species that are found growing on riverbanks with their roots growing into the river.
• Known issues: Not very popular culture, not a lot of information about this.


Terrestrial culture – orchids play dirty.
• Target parameters: Moisture rich, soft sunstrate.
• Target environment: varied, terrestrial orchids.
• Explanation: Not all orchids are epiphytic or lithophytic. There are several genera that are found growing along the forest floor, and even in meadowlands. These orchids are considered terrestrial or semi-terrestrial. Instead of grasping onto host trees, these plants grow either directly in soil, or in humus rich leaf litter in the forest floor. Replicating these conditions are easy for a hobbyist, as the growing habits of most terrestrial orchids are consistent with its terrestrial non-orchid neighbor plants.
• Known issues: Terrestrial and semi-terrestrial orchids tend to require more water compared to their epiphytic cousins. If overwatering is the prime killer of epiphytes, underwatering is the primer killer or terrestrial orchids.


There are also hybrids of the above cultures, specifically tuned for optimal growth conditions of the grower’s plants.
Some of these hybrid cultures include:
• Dry pellet culture – LECA pellets, lava rocks, fast drying rocks in a plant container with no water reservoir. This is a fast drying culture that provides excellent root ventilation. This can be considered a hybrid between mounting and semi-hydroponic culture.
• Pot and sphagnum moss culture - The pot contains only sphagnum moss. This is desired for water-loving plants that are grown in very dry conditions.

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