Friday, February 24, 2012

Converting Plants To Hydroculture

Here is a step-by-step explanation - with photos - on how to convert houseplants from soil to hydroculture. The information below has been written to help anyone interested in hydroculture fully understand the conversion process.

Let’s get started.


What Is Hydroculture?

Hydroculture is the method of growing plants without soil. You have most likely heard about ‘Hydroponics’, an automated method of growing plants in water, mostly related to the production of food. Hydroculture, related to hydroponics but functioning quite differently, is the low-end of growing plants in water. It is also referred to as passive hydroponics, which means that it lacks all the automation commonly associated with hydroponics.

The Equipment Used

The hydroculture system consists of five basic parts:

1) outer pot (for holding the water reservoir)
2) culture pot (inner growing pot)
3) growing medium (expanded, fired clay pellets)
4) water level indicator
5) nutrient (fertilizer)

Outer Pot

The outer pot (container) is a closed water reservoir that can be any size, shape or colour and is available in many different forms: ceramic, plastic, stone, glass, terracotta, etc. Any closed planter or container can be used as an outer pot as long as it’s impermeable and incapable of releasing harmful chemicals into the water. If you decide to use chemical-releasing containers, such as brass or copper, consider lining them with plastic to protect your plants.

Culture Pot

The culture pot is the heart of the hydro system, available on the market in many different sizes to accommodate an assortment of plants. Fitting snugly into the outer pot, it is made of plastic with slits all around the base that guarantee maximum air flow through the growing medium and the root zone. The design of the culture pot also allows for a water level indicator to be attached firmly.

With its concave bottom, only the external portion of the pot makes contact with the outer pot and the nutrient solution. The special design of the culture pot assures that the plant’s root are not growing in water; they are growing above the water, surrounded by the clay pellets, which draw the moisture up by capillary action from the supply in the outer pot. Roots are never wet, just evenly moist.

The Growing Medium

Clay pellets are the growing medium of choice. They take the place of soil, are porous, retain moisture and transfer water to the roots by capillary action. These pellets are light in weight, do not compact, are inert, ph neutral, contain no nutrients and are completely reusable; you can clean and sterilize them after use.

The pellets drain freely and don’t hold excess water, providing good oxygen levels around the root area. This growing medium called LECA (Light Expanded Clay Aggregate) also provides the necessary support for the plant along with its ability to absorb the correct amount of water and oxygen. Healthy and beautiful plants are guaranteed with this optimal ratio of water and oxygen.

Water Level Indicator

The water level indicator, resembling a thermometer, fits neatly into a slot in the culture-pot and is used as a water gauge. There are three markers on the indicator: min (minimum), opt (optimum), max (maximum). The marker in the indicator rises as water is added and falls as the water is used up by the plant. When the indicator reaches the minimum level, it signifies that the pot is completely empty and it’s time to add water. The water level should always be kept at the opt (optimum) level. Only under special circumstances should you fill the pot to the max (maximum) mark, such as extended absences from home.


Hydroculture plants have a regular feeding schedule, which eliminates the guesswork involved in traditional growing methods. Feeding frequency depends on which kind of plant food you decide is most convenient. The two basic choices are liquid fertilizer and slow release nutrient. Liquid fertilizer can be added at every watering while the slow release nutrient - loose granules sprinkled on top of the clay pebbles or a gelled disk that is placed in the bottom of the hydroculture water reservoir – is added every 4 - 6 months.


Prepare The Pellets

If you’ve just picked up a new bag of clay pellets, rinse them under running tap water in a colander or strainer to remove dust caused by shipping and handling. Likewise, clean pellets that haven’t been put to use for a long time. When the water runs clear, which signifies that the clay pellets are clean, soak them in water overnight – or at least for a few hours - to saturate them. If your pellets are not new, and they’ve been used recently, just rinse them a bit and use them right away.

Convert Only Healthy Specimens

No matter how hardy a plant, converting it from soil to water will cause it stress. If the plant is in poor shape the results will be less than satisfactory and the plant may even die, so choose only healthy specimens. In addition, do not convert plants that are infested by pests; get rid of the infestation first and convert the plant only after its health has been fully restored.

To Water Or Not To Water

Before you convert your plant, decide whether you want to let the soil dry out completely or whether you want to give your plant a hearty drink. there are advantages and disadvantages to both. A plant whose thirst has been quenched may be able to handle the conversion much better, but it will be more difficult to remove all traces of caked on soil from the roots. Those roots will eventually rot so it’ll be important to check the plant regularly below the surface. On the other hand, a parched plant will have a more difficult time dealing with the process, but the roots will be easier to clean. I personally convert my plants when they are dry, but my ‘practical’ advice to you is this: Water thin-leaved, thirsty plants thoroughly before converting and let succulents dry since they have the ability to store water and easily survive droughts.

Prune The Roots And Remove All Traces Of Soil

Remove the plant selected for conversion from its pot. If the plant does not slip out easily, squeeze the sides of the pot or use a knife or spoon to loosen the soil. Remove dead or unhealthy roots and prune back the
rest - especially the longer ones - about 1/3 to encourage new growth. Don’t be afraid of this step; as your plant grows new water roots, the soil roots will become useless either way.

Crumble away as much of the soil surrounding the remaining roots as possible. Remember to be gentle when you are working with the root system.

Once you have removed as much dirt as you can by hand, rinse the roots under tepid running water in your sink or bathtub to remove whatever traces of loose soil are left. Massage the root area with your hands to help with the cleaning but don’t be too rough.

For traces of soil that are too hard to remove, use a soft toothbrush, sponge or cloth and scrub lightly. You can also soak the root ball in water for several hours or overnight to aide in this process. Be sure that the roots are completely free of all traces of soil. Any soil left on the roots can lead to rot.

If it is utterly impossible to remove all the soil, even after a night of soaking, don’t fret. Clean the roots as thoroughly as you can and pot up the plant in hydroculture. After ten day to two weeks, disassemble the setup, give the roots another rinsing and repot.

Pot Up The Plant In The Culture Pot

Before you begin, install the water level indicator in the lining of the culture pot. Your plant is now ready to be added to its new container.

Pot it up the same way as you would in soil. Add a layer of clay pellets at the bottom of the culture pot. The amount of medium added can be an inch or two, maybe more. It all depends on the depth of your pot and how tall your plant is. The process is similar to the way you add some soil at the bottom of your pot before placing your plant on top of it in traditional growing styles.

Place the plant into the culture pot on top of the layer of pellets, spread the roots out across the medium and slowly fill up the pot, adding clay pellets to within ¼” of the top of the pot; this will anchor the plant.

Place The Setup Into The Outer Pot

The roots are clean, the water level indicator is inserted and the plant is potted. There’s only one thing left to do: move the whole kit and caboodle into an outer pot and add some moisture.

Pour water over the pellets until the water indicator reads optimum. Do not water again until the indicator reaches the minimum setting. Something worth remembering: clay pebbles retain moisture for a few days so don’t worry if you don’t add water immediately when the indicator reaches the minimum level; your plant will be fine.

What To Expect

The development of water roots may take anywhere from 2 - 12 weeks. During that period, there are a few things you can expect that are perfectly normal.

  • Most of the plants will react with some wilting but hold onto their leaves.
  • Some plants will go into shock for a short while and display minor symptoms of stress such as wilting, minimal leaf shedding and yellowing of leaves.
  • A very small number of plants will shed almost all of their leaves and grow new ones after they’ve converted.
  • The majority of flowering plants will lose their buds. You might want to consider converting these specimens after the blooming period is over.
  • A few plants suspend the growth process of emerging leaves, no matter what stage they’re in, until water roots form. Then they resume the growing process as if nothing happened. This is a truly amazing thing to witness.
  • A surprisingly large quantity of plants does not react negatively - at all. They are either oblivious to the conversion or - most likely - unconcerned. These champions grow water roots very quickly.

The reaction of each plant is unique; no two plants convert the same way. But no matter how your newly-converted plant reacts, don’t give up on it during this period. Whether it sheds a couple of leaves or hangs over its pot miserably, be patient. It will survive and bounce back. Never toss out a plant simply because of its dramatic display; chances are it is still alive.

How You Can Help

You are aware that until your plant grows water roots it will be a stressful period for it. Without proper roots it does not have the
ability to pull up water adequately, and will struggle to stay hydrated. You can make the transition easier. Below are a few things you can do to aid in the process:

  • Spray the plant several times a day with water to provide it with much needed moisture.
  • Place the entire pot on a pebble tray filled with water that will rise and surround the pot with humidity.
  • Cover the plant with a clear plastic bag until it converts to keep humidity high.
  • Keep the plant out of the direct path of the sun and drafts.
When To Start Feeding If you surf the internet, you will find differing information on when to start feeding your newly-converted plant. Some sites will advise to fertilize right away, others will tell you to wait until the next watering. It’s all good. My personal recommendation is to wait until your plant develops its water roots, which signifies that it has successfully completed the transition and fully adopted the hydroculture system.
The information above has been written to provide you with a clear understanding of what’s involved in hydroculture – the conversion of the plant (the most pertinent) and the equipment included. But unlike the medium, which is the core of the system and cannot be compromised, culture pots, outer pots, water level indicators and hydroponics fertilizers – the standard hydroculture setup – can be customized, and even compromised, to suit your needs. I personally prefer clear glass containers that allow me to monitor the water level thus eliminating the need for water level indicators and the use of double pots.

Now that you’re equipped with all the necessary information, what are you waiting for? Get growing with hydroculture.


  1. Wow, I couldn't even begin to do this! I envy you your green fingers...I kill everything I touch. I think I even kill plants in my sleep, I'm that good!

    1. Ha ha ha... It's just not your thing, that's all. Not everyone wants to have plants around the house that demand care.

  2. Why would you want to grow them in water? What reason is behind it?

    1. Eliminate watering blunders, not have soil pests to deal with, not have to buy any more soil, ever, etc, etc. There are quite a few reasons that are beneficial, but you have to like this system.

  3. Wow, this is a great step-by-step Martha :) My hubby surprised me with a very cute plant with small pink flowers (the leaves are very thick, hard and glossy) from the grocery store a few weeks ago... maybe he's giving me a subtle hint that we could use some life in the house?! I'm actually really enjoying it myself.

    1. Awwww, that is sweet. From the description, I wonder if it's a Kalanchoe. Sure sounds like it. I like having plants in the home, especially because our winters are so long and we're deprived of greenery and flowers for months on end.

  4. I heart you! I'm going to give this a try. May be I'll be able to grow something!

    1. This is pretty much fail-proof, so something will survive! LOL...

  5. That is totally amazing! i really enjoyed that AND learned a lot. The best part is that i know where it is when i need to get back to it - although i might just print if off. Thanks!!

    1. You're welcome, Francie. Don't be afraid to give it a try if you're ever tempted.

  6. Do you know of a source to buy the culture pots, outer pots, nutrients, and water level indicators? I have the growing medium already, but can't find a source on the Internet to buy the rest.

    1. Sorry, I don't have any source that I favour. There is one that seems to be a good supplier for hydroculture kits: Interior Water Gardens. I've never ordered anything from them, but it would be a good idea to shoot off an email and make some inquiries. And if you look up 'Hydroculture Kits' on google, you'll run across some on-line ordering sites.

  7. Yes, I did try that but the "kits" all include the growing medium and I don't need that. However, I think it is a good idea to email Interior Water Gardens and see if they can sell me the rest separately. Thanks!

    1. I hear ya...that is true. I've recommended this place to others and they tell me the same thing. But you're right; just go ahead and email them and see what happens. It certainly costs nothing to ask.

    2. can I convert A flowering plant back to veggie state

    3. Can I Convert A plant That's already flowering to it regular state

    4. I've never had to do it but I assume you can.

  8. I have found a source to buy the separate components: Outer pots, interior culture pot, and water gauge. It is called They also sell the growing medium and full kits of everything.

    1. Thanks for the link, Nancy. I know of that place but I've never purchased anything from them. It's a good source for people that want to try out hydroculture.

  9. Martha, I like the idea of the clear glass containers. Can you explain how you know when to add more water without the indicator? Thank you!

    1. Just let it run out and then refill right below the roots. And you can even leave it empty for a couple of days or so. The plants will be fine.

  10. Since I wrote the original comment in May 2015, the name of the Internet Store has changed to:
    The guy who runs it is really nice and helpful as well as selling the individual components. In response to MRH, unless you use clear glass pots, I don't know how you would tell when the plant needs water. Personally, I am not too fond of clear glass as many plants do not like their roots exposed to the light.

    1. Thanks, Nancy! I will have to check them out.

      And you are right. You can only see the water level in glass containers.

  11. Hi have a look this nice hydroponic indoor garden bye

  12. Does it matter much what time of year I convert plants? I'd like to do some now (fall) but am wondering if I would be well-advised to wait until spring.

    1. Conversion causes stress to plants at any time but because they're not very active during the colder months, the stress is higher from now until spring. I've converted plants year round but I wouldn't recommend it. The best time is spring.

  13. Im trying this out now. How do you prevent algae formation especially when using clear containers? And if i did develope how canni remove it? Thanks a lot for this!!

    1. You would have to place the clear container in an opaque one. I used to also create a mix with hydrogen peroxide and add it to the water, but it's been so long since I've done it, I honestly don't remember how! Sorry. Good luck!

  14. This is so helpful especially your last line about clear containers because I've been searching everywhere wondering if I could do it that way. Thank you so much.

  15. Do you have a recommendation for nutrient solution for hydroculture? Not sure what to put in with the leca.