Growing Orchids in Water? Complete Guide for Beginners

Sphagnum moss along with charcoal, peat, leca pebbles (sometimes called Hydro Clay pebbles), and Styrofoam peanuts are usually the most common potting mediums found for orchids. There is another medium that is becoming extremely popular, and that is growing the orchid in water or hydroponic media/culture.

Can you grow orchids in water?

Water a decent medium for orchids to grow in, but there are special requirements and observations that are involved. Growing orchids in water is actually a simple technique. Any signs of either dehydration or root rot must be acted upon quickly, since the roots are more prone to root rot.

Video: The Difference Between Semi and Full Water Culture

Can any orchid adapt to hydroponics?

The best orchids to transfer to a hydroponic culture are ones that you have newly acquired or are still young. If you have orchids that you’ve kept for years in potting medium, and they’ve adjusted well to this, I wouldn’t try to change the medium. To do this, would be to force them to adapt to new surroundings and radically change what they have done for years already—talk about a mid-life crisis! Choose orchids that are new or just picked up from the store.

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Epiphytic orchids the species that most adapt to hydroponic growth, since their thick, spongy roots are exposed to air in their natural habitat. Terrestrial orchids will not adapt as well to this method, since their roots are designed to pick up nutrients in the soil, and not through the air.

What are the cycles or rotations of dryness and watering?

There are two methods to hydroponic orchids.

In the first, named full water culture, there’s nothing in the pot besides the roots and water. Use a watering cycle, so the orchid has some wet time, and some dry time. Each orchid (not species, or genre, but each individual plant) will have their own preferences. You will have to experiment with what makes each specific plant thrive and repeat those conditions.

For starters, you can begin with a two-day watering cycle, to a five-day drying out cycle. This mimics the irregular rainfall that can be found in some forests, where rain is unpredictable and sporadic. Verify the conditions of your orchid, and see how it responds.

Note: orchids are extremely slow growers, and adapt very sluggishly. You cannot verify this method in only a week or two. This will take time.

For example, to test a change in potting medium, it usually takes a six months to a year to see if the orchid does well or not. And every time you replant or transfer the orchid to another (new) potting medium, it sets its growth back a few months. As in therapy after a life-crisis, adaptations aren’t made in a week’s time.

Think about it from the orchid’s point of view: you’ve just ripped out the whole foundation that the orchid once knew. Don’t expect it to thank you, even though you’re providing it with something better. Give the orchid time to experiment change, find a creative way to adapt, and then improve on it by creating specific roots for the water culture. In time, it will see that the change made it grow better.

Come to think of it, isn’t this the same process with our Creator, too?

The second method, sometimes referred to as semi-hydroponic, is when the orchid pot has a layer of water present all the time in the bottom of the pot, as the orchid sits on a layer of leca pebbles (organic expanded clay pebbles). The roots don’t ever come into direct contact with the water, but the pebbles soak up the water, so hydration and humidity are present and constant.

In this method, you’ll exchange the water from time to time, refreshing the continual water reservoir in the bottom of the glass bowl. Some orchid growers exchange the entire water on a weekly basis, others on a biweekly basis. Again, each orchid will show whether it is adjusting well to the hydroponic system, so experiment and see which ones the orchid responds to better.

How do I transfer and orchid into a hydroponic culture?

Take them out of the plastic pot, and remove all the sphagnum moss that is stored (usually packed) in the roots. I need to emphasize the importance of removing ALL the moss, debris, pine bark…everything.

It all has to go.

When orchid growers pot orchids to sell them in department stores or local shops, they focus on the least amount of investment for their money. They start out with a tiny, fragile plants sitting in sphagnum moss, since it is usually the best indicated medium for new plants.

Every time you manipulate and handle an orchid, it retreats and suffers a bit. This means that the less the orchid grower has to touch the plant, the better. To replant with new medium when the orchid has outgrown its pot will also increase their costs, since now there’s twice the expense. To avoid this, they stuff more sphagnum moss around the outer side of the pot, leaving the older, more decomposed moss still in the pot.

When you take out all the moss, you’ll most likely see the two phases of the sphagnum: the outer will be easier removed, and the inner layer, which is more tightly compressed, will be stuck in the plant and compacted in between the roots.

To more easily remove this moss, you can leave the plant soaking in tepid water for twenty minutes. This facilitates the removal, since sphagnum will tend to float.

For emphasis: every piece of potting medium must go—all of it.

This is the most important part of transplanting the orchid. When you leave even the tinniest part of bark, moss, or other material, when it is transferred into the hydroponic system, the left-over material will decompose in the water and promote root rot. This is the perfect chance for bacteria and mold to grow, leaving the door wide open your orchid to suffer later on.

Funny to mention it, but it’s kind of like old relationships. Make sure you’re totally free from the last relationship before you move on to the next, because that one little slither that was left behind will ruin the whole environment if not taken care of properly.

In our orchid case, that means get rid of any signs that it was ever there. Delete photos, wipe out emails, and get rid of the potting medium. Start new; start fresh. New slate to work with.

Don’t rush this step.
Soak your orchid several times, fifteen to twenty minutes a time until all the potting medium is free of the roots. You can do this step in one or two days if you’d like, but make sure it’s all clean.

Once the orchid is free of the old potting medium, you now need to analyze the roots. If there are any roots that are squishy, molded, or discolored parts. Use sterilized scissors for this part, making sure to not add any new points of open infection to the orchid.
 It doesn’t matter if there are four or five roots left over in this process, and all the rest had to go. It’s better to have a few good healthy roots, than more unhealthy ones that will contaminate the whole environment. One rotten orange contaminates the whole batch—same with roots. Get rid of anything that looks damaged, is old and nonfunctional.

For this part of the transplant, it is good if you’ve had some orchid experience before. If you have never had an orchid before, I suggest to not do hydroponics as your first. Maintain it in it’s potting medium and once you have some experience and know what signs to look for when trimming away roots, then start with hydroponics.If a part of the root is extremely damaged and spongy, you can strip away the outer coating leaving a fine, wire-like root, without the velamen. Even though this method will seem harsh, the root will survive, and can still absorb water. The final aspect will be quite unnerving, and the orchid will not like this method, but it is a solution to keeping one or two more roots when possible.

What pot do I use with hydroponics?

For either the pebble method (semi-hydroponic) or the full water culture method, look for a taller jar with long, high-curved sides. Any circular or globe-shaped glass with a narrow “mouth” will do. This shaped-design will trap the humidity yet allow sufficient air flow.

It all comes to the surface area on the top. The more surface area exposed to the outside environment, the faster water will evaporate. We don’t want fast evaporation.

Wide, shallow baking-pan like jars have an open surface area that is exponentially expanded. Stated simply, avoid wider jars that can promote evaporation quickly. A taller jar is preferred for the same reason—shorter ones make the pathway to external environment easier for humidity to escape, therefor, will make evaporation easier.

For the pebble method, think of a whiskey bottle (without the narrow top) and how long it would take to the water droplets to travel upward, towards the narrow opening. This is the perfect example of a jar to mimic—compared to the shallow, wide, baking pan-like jars.

Another non-negotiable detail: the material must be clear. Either glass or plastic is perfect. This allows you to observe closely the orchid growth and how it’s adapting to its new environment. For water culture, you need to be constantly observing the orchids and how they are adapting.

The last thing you need to be aware of is the size of the bowl. For full water hydroponics, transplant the orchid into a pot where the roots will reach the bottom and the leaves are sitting outside the top, next to the basin. For semi-hydroponics, the basin must be taller, allowing space in between the roots and the water reservoir.

How much water do I fill the pot with?

For a full water culture, you need to focus on one more detail: expansive air flow around the roots. A round fishbowl-like jar would be best, since water is meant to evaporate fully and have sufficient air space for a nice draft of air. Holes drilled on the side s of the pot are mandatory for this.
In the small layer of pebbles method, efficient evaporation will be the key to success. This answer is based on two variants: 1) how many pebbles and 2) how much water.

Add pebbles well over ½ to ⅔ of the height of the jar. You need to maintain water at the constant height on the bottom ⅓ of the jar, preferably making a marking on the glass. Keep watering daily (or every other day) to keep the water at ⅓ (during winter decrease this to ¼) of the pebble height, far away from the roots.

Exchange all water weekly.

Never allow the water to evaporate completely, since the roots aren’t in direct contact with the water. You don’t have to worry about root decay with this method, which is a plus. Of the two methods, this is the easiest for the beginner to start with.

In the second method, the bottom of the root is in direct contact with water for two days, then left to dry out for five days. There are no pebbles or marbles—it’s just water. This method can induce root decay and root if not strictly observed.

This method requires you to focus on the quality of the water you are using. In some places, cities have added so many chemicals for water treatment and purification) which actually aid humans) but to the orchid are not pleasant.

For this reason, you can either: 1) get rain water, or 2) fill up a basin with water and let it sit out overnight. This will ensure that the harmful chemicals evaporate into the surroundings, leaving the water perfect for orchid usage. And 3) use distilled water, available at supermarkets and grocery stores.

What are some of the signs that my orchid is not adapting well to hydroponic culture?

For a full water culture, you need to focus on one more detail: expansive air flow around the roots. A round fishbowl-like jar would be best, since water is meant to evaporate fully and have sufficient air space for a nice draft of air. Holes drilled on the side s of the pot are mandatory for this.
If the orchid is having an extremely hard time adapting to its new potting medium, its last resort might be a chance to reproduce and pass its genetic material on to another plant. It sends out a flower before it gives up hope in life.

If an orchid had a brain, it might say something like this: I can’t live in these conditions. It hurts too much. I’m giving up. My last distress signal is a flower in hopes that my species lives on. Result: a flower.

If you see a flower stem, don’t be convinced that hydroponics has a positive result quite yet. You may keep it in the hydroponic medium for a year or two and then compare results. Are there more flowers? Are the leaves healthy, plump, fungus-free, and giving off a vibrant vibe that they love the conditions you have given them?

One of the first signs of trouble are root decay. This is why constant observation is so important.

The second indication is that leaves may turn yellow, or have discolored patches. Fungal infections are usually the cause. Bacteria and fungus grow by ⅓ in a hydroponic set-up. You need to be quick to recognize it, and start treatment immediately.

The other possibility for the yellow leaves (assuming it isn’t too much direct sunlight or low temperatures, which both turn leaves yellow) is over-watering in a non-hydroponic set-up—so imagine in a full water culture. Excess humidity and irrigation are killing your orchid. And how to fix this problem with hydroponics? Good question. I’m still researching this one.

If the orchid sends out a new flower, you might think that the hydroponic or semi-hydroponic system has worked well for you. I hate to be bearer of bad news, but this could mean a clear sign of stress, too.

Why are many orchid growers against hydroponic methods?

There are a lot of cons to hydroponics.

To start off, hydroponics will not save you time. If you switch to a hydroponic or semi-hydroponic method thinking you’ll be watering less, or it will be a more “hands-off” approach, it won’t be. In fact, it is more time consuming, and you have to double your observation of the roots, so it will be more time-consuming, not less.

The second con with using this method, is that you have to have some skill in recognizing problems immediately, and a new beginner orchid grower will take some more time to acquire this skill. Root rot will spread quickly, killing the exposed roots before you will have time to recover them. The orchid is already in a highly-stressed state because it’s medium (and foundation have all changed drastically) and to acquire bacteria growth, mold, root rot and decay, don’t promote the best environment for the orchid.

The third con is that some orchids require the entire roots to be humid, not only the bottom roots. Many phalaenopsis are in this category. While the bottom part of the roots is saturated, the top roots are nearly drying out. This can be to low humidity environments with a constant air-conditioner running, which usually is the case inside most homes.
This is why they prefer the sphagnum moss, pine bark, charcoal potting mix. The extra coating in the top layer also provides a place to store humidity. The distribution of the humidity is better with another potting medium.

Again, think of the orchid’s point of view: the top of the orchid is dry, while the bottom sits emerged in water. Not only does it have to adapt to no potting medium (which is a loss of foundation and stability) it also has to adapt to two very different humidity clashes within the same root. That’s a lot of adaptation.

If you have kids at home or are a teacher:

I happened to come across this 29-page book available to view in PDF form about hydroponics in the classroom. You can view it by clicking here, which will lead you to the PDF version of the book. (Source: Exploring Classroom Hydroponics, Growing Ideas, available through Science.gov) Not only does it explain all the ins and outs of hydroponics, it also has several experiments that can be made by children at home or in the classroom setting.

Just so you know, I don’t get a commission or any affiliate marketing for sharing this sharing. I just thought it was awesome and wanted to share someone’s hard work. It might be a little outdated as in format and style, but the information hasn’t changed much since 1995. So I do suggest you take a look at it.Now that you know all about hydroponics, what to look for when transferring an orchid to its new medium, and how properly water it, it’s time to get your hands dirty. Check out some of our tutorials on how to design a great floral design or build a terrarium with orchids. If you’re not sure if hydroponics is for you, check out our other potting medium articles, like sphagnum moss and charcoal.

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Happy cultivating!