5 common mistakes to avoid when growing your orchids in-doors

Author: Aaron Chen  Date Posted:3 February 2020 

There is no doubt that orchid hobbyists cherish their orchids by taking care of them carefully. However, newbie orchid growers usually make some mistakes in the learning process which can be disastrous and kill off precious orchids.

In order to prevent this tragedy from happening, we co-authored with Ken Siew (an experienced orchid hobbyist and professional orchid grower) and created this blog post, hopefully it helps you avoid the deadly mistakes and enables you to grow your orchids healthily and have beautiful blooms.

1. Exposure to too much sunlight

It is well known that orchids are shade loving plants and you shouldn’t let them be exposed to too much sunlight. The harm to an orchid is huge when exposed directly under the fierce sunshine in hot summer. For example, phals (one of the fastest growers in the orchid family) grow best under indirect sunlight and it’s best to place them in a south or east-facing window and indentify which provides your orchid with the right amount of sunlight. You can observe its leaves.

The ultimate solution is to put your orchid in a shade house or glasshouse, but which one is the right solution for shade protection?

Shade House and Glasshouse

The simplest form of orchid housing is usually a shade/bush house which provides shading from the top and sides. A shade house reduces sunlight to produce light intensities that make it closer to the ideal temperature for tolerant plants such as cymbidium orchids. The shading environment reduces the heat associated with sunlight, depending on the type of shade material used. This shade material will also decrease some of the airflow.  

It is possible to use certain materials such as shade cloth to expand the range of plants grown under these conditions beyond cymbidiums and other simple-to-grow orchids. An increase of shade and humidity alone will allow successful culture of cold tolerant “softer” plants such as oncidium and paphiopedilum. It is possible to create microclimates within a single structure to expand the housing for a wider variety of orchids.

The use of solid, transparent, non-porous materials such as UV-stabilised fibre coverings or glass to replace some, or all of the shade cloth, either seasonally or permanently, will allow a great many more varieties of plants to be grown. A solid roof that provides protection from the rainy season is almost mandatory so flowers can be kept perfect.  

A airtight glasshouse allows the space to be heated efficiently, but usually it is not economical heating a space unless it is sufficiently large, waterproofed and well-insulated.  

You can learn “The difference between shade house and glasshouse” from the article here

Shade Cloth

Shade cloth is usually supported by a frame to provide shading for orchids from above. It is made in different grades which allows for optimal shading for different orchid species. The presence of trees or buildings on one or more sides of the growing house would dictate that those sides affected may need less shading.  

Learn “How to choose the right shade cloth that will make a difference to your plants” by clicking here

In a nutshell

With the options provided above for shading, you can prevent your orchids from being destroyed by the sun and rain if you:

  • are a savvy D.I.Y.er, build a frame and buy some shade cloth;
  • want to have an enclosed area, which protects your orchids from wind, hail and pests, go for an easy to assemble shade house; for winter place a plastic fabric over the shade house.
  • want a heated space in winter then go for a glasshouse in the backyard; but then you may have to place shade cloth over your glasshouse in summer.

2. Over Watering

One mistake that beginner orchid growers often make is excessive watering. Beginners can be over enthusiastic in terms of overwatering their plants. For instance, phalaenopsis orchids only require a limited amount of water to survive and grow, and they are more than likely to experience problems such as root rot when overwatered. Therefore, only water your orchid with three cubes of ice each week, or equivalent to 1/4 cup of water.

You can learn “when and how to water your orchids” from the article here

3. Insufficient Humidity

Almost all orchids appreciate high humidity, so when there isn’t enough humidity in the growing environment, some severe damage maybe caused to an orchid.

Humidity is determined by how much moisture is put into the structure versus how quickly it dissipates from it. It is a consequence of frequency and volume of watering or misting as well as air flow between the inside and outside.

Humidity is also the most under estimated variable for a successful culture. The vast majority of orchid species derive from the temperate belt around the equator where humidity is highest. Species which derive from higher altitudes can be sufficiently tolerant of cold and able to be grown outside their native zone but for best success, humidity of the ambient air needs to be addressed.

The ambient conditions such as temperature and dryness of the air outside the growing structure are important. If the humidity is high and temperatures are dropping, condensation will result. Condensation on flowers may cause damage so it is essential that misting be done early in the day rather than late.  

Plants such as the Oncidiinae, the Vandaceous group and Paphiopedilums often are cold tolerant but can languish if the humidity is not improved. The ideal humidity for most of these plants, and indeed most orchid plants is from 60-80% and possibly more during hot seasons.

Humidity is controlled by air-flow and watering. The simple expedient of blocking off some of the air flow, even if on one side of the growing structure, will instantly result in higher humidity.

Ambient humidity is generally below the ideal for orchids in most areas of Australia except for the far North. The higher humidity of enclosed or partially enclosed structures means there is fewer requirements for watering and that watering or misting results in a more persistent elevation of ambient humidity around the plants.

In a nutshell

If you are living in an area that has low humidity, providing artificial humidity for your orchid is one of the most important methods to keep them healthy. Adjusting humidity could be accomplished by misting your plant from time to time, by placing a humidity tray underneath its pot and controlling the air flow into the orchid growing structure.

4. Imbalanced Heat, Humidity, Light and Air Flow

A balance between light, heat and humidity has to be achieved for optimal culture. When it is imbalanced, the growing environment for orchids needs some improvement.

Heat and Humidity: Closing up the growing space restricts airflow and increases humidity and temperature.  Humidity can be increased with frequency of watering or misting but unless some containment of the humidity is provided, it is lost quickly if the outside air is hot and dry.

Temperatures can rise quickly in a glasshouse when in full sunlight if no cool air replaces the heated air within. For this reason, most hobby growers ventilate their glasshouses during daylight and close them up at sunset, in all but the coldest climates.  

Heat and Light: They are inextricably linked to each other and are largely controlled by shading and controlling airflow. Generally speaking, orchids are light-hungry plants and should get 12 to 14 hours of light everyday throughout the year.

Natural light always comes with heat, however, in the tropical area, the duration and intensity of natural light does not change as frequently as it does in temperate climates. Therefore, you may have to move your orchids around, by placing them inside or outside of a shade house or alternatively provide the orchids with artificial light to keep them happy in winter.

Some orchids require a huge amount of light, such as vandas and cymbidiums (high-intensity discharge lighting is usually required in order for them to flower).

The ideal spot for growing orchids is either south or east-facing windows. Usually west windows are too hot while northern windows are too dark. Placing orchids under artificial lights is the last resort if you can’t find a good location to grow your orchids.

Heat and Air-flow: The temperature of the interior of the growing house can be stabilised (less rapid changes of temperature) by decreasing airflow.  The reduction of airflow will also minimise “wind-chill” (i.e. forced evaporation by moving air). It should be remembered that air-flow is important during photosynthesis and that during daylight hours sufficient moving air be provided.

In a nutshell

Heat, humidity, light and air flow share close relationships with each other. In order to have a better performance in a orchid’s growth, each of them has to reach a certain level so they can be balanced to create a optimal growing environment for your orchids.

5. Planting orchids in wrong potting materials

Using soil to grow an orchid is a mistake made by beginners that can kill the plants. Planting materials for orchids is not the same with planting materials for houseplants.  They should drain rapidly and allow good air circulation at the roots. Experienced orchid hobbyists usually use a various range of materials such as bark chips, spaghnum moss, coconut husks and styrofoam to replace potting soil.

For example, phalaenopsis orchids grow on trees when they are in their natural habitat, and therefore, they should not be planted in soil. Potting medium like tree bark, cork, or coconut shreds that allows sufficient air circulation around their roots suit phalaenopsis orchids the best.

To choose the right potting mix to grow your orchids, you can learn more from this article

In conclusion

Growing orchid’s in-door is quite different from growing other house plants, but it is not as difficult as you may think. Everyone makes mistake, but you can save your plants and learn from other people’s “deadly” mistakes by picking the right combination of shade structure to avoid excessive sunshine, control watering, adjust humidity level, balance heat, humidity, light, air flow and choosing the right potting mix for your orchids.

Don’t give up after failing the first time in growing orchids, be persistent and experiment with the above in trying to look after your orchids, and I am sure that all your effort and investment will pay off.

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