Semi Water Culture Orchids

Semi Water Culture Orchids

Orchid water culture is when you grow the orchid in water only, without any kind of growing medium. The only materials you need for a simple water culture setup are the orchid, a glass container and water.

In semi water culture, you place the plant in the vase of water up to the top roots, making sure that the water does not touch the stem. You will keep the plant in the water for two or three days and then empty out the water and let the orchid sit in a dry vase for the next five days.

In this article, we will discuss how semi water culture is done, its pros and cons, as well as other water culture methods you try at home.

Can you grow orchids in water?

Yes, orchids can be grown in water. Despite being quite particular about their growing medium, orchids do quite well when grown in water, if it is done correctly.

If an orchid’s potting medium is constantly soggy, it can lead to root rot and the overall deterioration of the plant.

Bark mixtures are most commonly used by growers to avoid excess moisture, but one could argue that water culture is more effective.

Some orchids can grow without a growing medium the same way they do in their natural habitat, but there are varieties that are terrestrial and prefer growing in soil. Either way, most orchids do fine in a commercially available orchid potting mix.

Water culture is an option even for novice orchid growers. When you add water into the container with the orchid plant, a humid environment is created, which is what orchids love. The wide mouth of the container also allows air to flow in and out with ease.

You may need some patience and a fair amount of research if you plan on giving water culture a try, but if you get the hang of it, it is a fun and interesting way to grow your orchids.

What is semi water culture?

Semi water culture is when you cycle the orchid plant between wet and dry days alternately. The number of wet days to dry days will depend on the living conditions of the plant.

One cycle can be three wet days followed by two dry days, or two wet days followed by five dry days.

Using a clear glass container with a large mouth, start the plant off with the first cycle option and see how your plant reacts. The longer you do semi water culture, the more you learn about what the correct cycle will be for your orchid. If mold starts to appear when you have three wet days, taper it down to two days. If the roots start to look dry after five dry days, shorten it to four days. All plants are different, and not every household has the same climate, so you need to figure out the most suitable schedule for your plant.

On wet days, submerge approximately three quarters of the roots in water in the glass container, but make sure that the water does not reach the stem. On dry days, empty out the glass container completely.

The advantages of semi water culture are fewer problems with rotting and mold, because you are allowing the plant to dry out periodically. Because you are alternating between wet and dry days, you are basically simulating the plant’s natural environment. In the rainforests, orchids get periods of rain followed by periods without rain. Another advantage of semi water culture is that there are fewer pest problems than with normal potting mixes.

The disadvantage of semi water culture is the constant schedule of emptying the glass container and refilling it. There is also the risk of forgetting to empty or refill the container, thus either risking root rot or underwatering the plant. Following the schedule can be a lot of work, especially for people who are quite busy in their day-to-day lives. The constant emptying and filling of the containers can also be tiring if you have multiple orchids growing in multiple glass containers.

What are other water culture methods?

Full water culture

In full water culture, the orchid is kept in a glass container of water 100% of the time. In this case, however, only a quarter of the roots are submerged in the water.

Make sure you keep a mark on where the water level should be. If the water evaporates, fill the container back up to where the line is. It is important that you keep the water level the same at all times.

The roots do not get completely dry unless, maybe a few times a year, you happen to forget to refill the water.

The advantage of this method is just how low-maintenance and convenient it is. Just place water in the container and you are all set. You then just need to check on the water level and add water as needed. This method also has less chance of pest infestation than orchids in normal potting mixes.

The disadvantage of this method is the risk of rotting and mold, because the plant is constantly exposed to humidity. You need to keep on the lookout for possible rot or mold problems so you can treat them immediately.

Semi hydroponics

The semi hydroponic method is different from the other two methods because here, you are adding clay pebbles into the container as well as water.

The pebbles are added to provide support for the roots and stem of the orchid. You will also need to solder or drill air holes just above the water line. The holes will provide better air circulation around the plant’s roots and keep them from rotting and developing mold.

It may come as a shock when the old roots die and rot during the first couple of days or weeks after starting this method, but do not worry because this is normal and expected. The plant will grow new roots that will adapt to the new environment you have set up.

The advantages of semi hydroponics are the convenience and easy upkeep. All you really need to do is to maintain the water level. The air holes in the container also provide the roots with great air circulation, and there are also noticeably fewer pest problems than with normal potting mixes.

The disadvantages of this method are that it can be quite tricky to set up in the beginning, and you may have to do a fair bit of research before trying it out. If you have multiple orchids that you want to grow using this method, it may take some time to set them all up.

How do you transfer an orchid to a water culture setup?

  1. If you want to give water culture a try, gather some clear glass containers, preferably those that have wide mouths and not ones that taper at the neck. The opening has to be wide enough to enable good air flow and for the leaves to be able to rest easily on the rim.
  2. The container should also be big enough to accommodate all of the roots. It is always better to use a bigger container than one that is too small. Make sure to wash the container with warm water and soap before using it.
  3. Next, take the orchid out of the pot and remove all the soil or potting medium. Rinse off the soil with water if you need to. Using a pair of sterilized scissors, cut off any dead and mushy roots. Remove any old leaves from the bottom part of the stem.
  4. When you have cleaned the orchid’s roots well, spray them with 3% hydrogen peroxide to kill any bacteria and mold.
  5. Place the orchid in the glass container and add as much water as required.
  6. For semi water culture, make sure the water covers about three quarters of the roots.
  7. For full water culture, make sure the water covers only one quarter of the roots.
  8. For semi hydroponics, make sure the water is just below the longest roots of the plant.
  9. When you first start water culture, do not be surprised if the old roots die off; this is normal.
  10. Be patient and soon enough the plant will acclimatize to its new environment.
  11. In full water culture, there is a higher risk of developing mold or rotting issues, so make sure you are always on the lookout for possible symptoms. If you can see white mold on the orchid, wash it off with lukewarm water and spray the area with 3% hydrogen peroxide.
  12. If the water in the container is starting to look cloudy and smell bad, dump out the old water, wash the container with soap, rinse well, then refill it with clean water.
  13. Check the pH of the water; orchids like a pH between 5.5 and 6.5.


Semi water culture is a type of water culture wherein three quarters of the orchid’s roots are submerged in water inside a clear glass container, for two or three days. The container is then emptied and the plant’s roots are left to dry out for three to five days.

The exact number of wet and dry days will depend on the type of orchid as well as on the local environment. If the humidity is low, you may have to reduce the dry days because the roots will dry out quickly.

Semi water culture can be a bit of a chore to implement because you will need to empty and refill the water every couple of days, but if you have no problem following a schedule, it is a great way to grow your orchids.

Image: / Emilija Randjelovic