Ah, orchids…some of the most beautiful flowers that exist. Their balance of colorful blooms and woody, thick roots make them a favorite flower of gardeners around the world.
A little-known fact about orchids is that in many areas of the world, they grow hydroponically in nature!
How is this possible? Well, in tropical climates, orchids typically grow between rocks or tree bark. Because the climate is so wet and rainy, they get more than enough water, and when its’s not raining their roots are being exposed to the oxygen they need to survive. Because other organic matter is decaying where they set roots, they also get the nutrients they need.
This is why you see orchids grown in a manner that is far different from most other flowers.
Let’s take a look at how you might get started growing orchids hydroponically…it’s easier that you might think.
Lighting for Orchids
As with any hydroponic garden, the goal is to mimic a plant’s natural growing conditions and, if possible, improve on them. For orchids, you need to replicate the air flow, water, light, nutrition, and humidity that they get in nature. Let’s start with lighting.
For most orchids, a 400w high pressure sodium or metal halide light will work just fine. If your particular species prefers lower light, just place them further from the center of your lamp.
Choose grow lights that put out a lot of blue light for the vegetative growth phase, and switch to a warmer light bulb when they begin to flower.
After your orchids flower, you can take them out from under the light and put them on display anywhere (and everywhere) in your home.
Grower’s Note: Growing orchids under powerful lighting causes them to use more water, so be sure to water more often. You’ll know when you should water your orchids when the roots are nearly dry.
They also use up more nutrition due to their increased growth rate, so you must feed them more often. A high-quality hydroponic nutrient will suffice.
Orchids require a good deal of fresh air and air circulation, especially when grown under high-intensity lighting. They also require high humidity, which makes them susceptible to various types of fungi and molds. To keep the humidity high, you can place plastic sheeting on the walls to trap in moisture. If you choose white sheeting, you also have a side benefit of light reflection.
It is mandatory to add a fan to your hydroponic orchid garden to keep air moving so these pathogens and diseases don’t develop on your orchids.
Growing Media for Orchids
If you haven’t had a chance to read up on hydroponic growing media, go ahead and do that — almost any of the most popular types work well for orchids. However, here are a few of the most popular ones:
Expanded Clay Pellets
- Extremely stable in both pH and EC
- Made from 100% natural clay
- Pre-washed to aid in stability
Expanded clay pellets are the most popular choice, and for good reason. They’re uniform and porous, with good water retention as well. You can purchase them in a few different sizes as well based on the growth of your orchids. Because they’re expanded clay, you can reuse them time and time again in your garden, unlike other mediums.
Learn More: Expanded Clay Pellets Growing Guide
Perlite and Vermiculite
- Helps loosen heavy soils and prevent compaction
- Aerates soil and promotes root growth
Perlite and Vermiculite are usually mixed with other media, like peat or bark. They’re so light that they need something with more water retention and mass to give your orchid roots something to cling to. Both of these are a great choice if you are growing orchids with thinner roots.
Rockwool is a great choice if you are having trouble with water retention, as it holds a massive amount of water. In fact, this is one of the problems of using it…you may waterlog your roots if you don’t water carefully. Nevertheless, it’s still a popular media for hydroponic orchids.
Last but not least, you are free to mix and match these growing media with others to create the perfect environment for the particular variety that you are growing. Because there are so many different varieties, it’s impossible to give a general growing media recommendation — you will have to experiment for yourself!
Learn More: Is Rockwool Harmful?
Hydroponic Systems to Consider
The simplest way to grow these beautiful flowers is going to be a wicking system or the Kratky method. It’s not a good idea to grow them in systems that allow for multiple plants, because you’re probably growing many different varieties of orchids, all of which require their own specific nutrients or growing media. On top of that, the last thing you want to do is let disease, fungus, or bacteria prey on your entire garden in one fell swoop.
Whether you’re a beginner to orchid growing, or an orchid-obsessed gardener, growing orchids in a hydroponic system is a great way to enjoy these marvelous, gorgeous flowers.