Normally you keep your houseplants in normal potting soil, which is composed according to the needs of the respective species. Such plants must be watered regularly and with great care. Plant care can be made much easier with hydroponics or another water storage system.

Many indoor plants also thrive without soil

Table of Contents

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  1. the essentials in brief
  2. What is hydroponics?
  3. benefits
  4. Suitable plants
  5. Materials needed
  6. Rearrange houseplants
  7. Maintain and repot
  8. Alternatives to hydroponics
  9. frequently asked Questions
  10. Does hydroponics have any disadvantages?
  11. What is the white film on the substrate?
  12. Is it true that hydroponic vegetables don't taste as good as soil culture ones?
  13. What do I do with my hydroponic plants when I go on vacation?
  14. How do you know if the water level indicator is broken?

    15. the essentials in brief

    • In hydroponics, plants are grown in water; expanded clay (19.73€) often gives the plant support.
    • Hydroponics has many advantages: overwatering is impossible, pests are rare, and humidity is increased.
    • Almost all plants (from orchids to tillandsia to cacti) can be grown hydroponically.
    • Even vegetables can be grown hydroponically.

    You don't need a green thumb for plants to grow healthy and beautiful. All you need is the right system and a little attention.

    What is hydroponics?

    The term "hydroculture" is made up of the two words for "water" (Greek: hydor) and "cultivation" (Latin: cultura), so strictly speaking it means "water cultivation". Hydroculture can thus be seen as the antithesis to classic soil culture. After all, plants need nutrients, water and air - but not necessarily soil for all of this, after all, with sufficient nutrition, the substrate only fulfills the function of a root holder. However, the plant also finds support in other materials, such as expanded clay, and therefore does well without conventional potting soil.

    What are the advantages of hydroponics?

    But why do you cultivate your houseplants without any potting soil? The answer to this question is quite simple, because hydroponics offers a whole list of advantages:

    • You have to water less.
    • You can water your plants precisely because the plant can always get as much as it needs.
    • Overwatering or forgetting to water is hardly possible.
    • Water requirement is shown specifically.
    • This keeps the plants healthier and live longer.
    • Pests hardly stand a chance on healthy plants.
    • The substrate can no longer acidify or silt up.
    • Increase in humidity in the room.

    In addition, a hydro system simplifies the care of the indoor plants during the holiday, because in this case you simply water them in advance and are no longer dependent on a holiday replacement. This is why hydroponic plants are so practical, especially in offices - everyone can check here when it's time to water them again.

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    Hydroponics for allergy sufferers

    Another advantage is that mold and terrestrial pests such as weeping flies can no longer develop in the clay granules. Hydroponics are therefore also very suitable for allergy sufferers who have always suffered from health problems due to soil culture and have therefore avoided indoor plants.

    Which plants are suitable for hydroponics?

    Until a few decades ago, the choice of plants for hydroponics was still quite limited, but nowadays almost all species can be cultivated without soil. In addition to the usual green plants, which we present to you in the table below, even orchids and cacti thrive in a soilless culture. The year-round blooming orchids such as the uncomplicated Phalaenopsis (also known as butterfly orchid) or the lady's slipper (Cypripedium calceolus), which is somewhat more delicate to care for, are particularly suitable for such a plant, as these species can be kept warm all year round and do not need a break. Hydroponics are also good for tillandsia.

    You need to pay attention to these points when caring for orchids in hydroponics:

    • Orchids are very sensitive to water.
    • Therefore, only fill the water level up to half of the optimum mark.
    • If the watering indicator drops to "minimum", wait two to three days before refilling with water.

    Many plants are suitable for hydroponics

    These green and flowering plants thrive particularly well in hydroponics:

    kind Latin designation origin location temperature maintenance particularities
    tree friend Philodendron South America bright, but avoid direct sunlight at least 12 to 15 °C high water demand high humidity
    begonia begonia equatorial regions partially shaded to shaded normal room temperature water moderately perpetual bloomer
    birch fig Ficus benjamina India and Nepal bright, but not directly sunny not colder than 15 °C water moderately, do not take hard water likes high humidity
    bow hemp Sansevieria Africa bright 20 to 25°C low water requirement various types, air-purifying
    Dieffenbachia Dieffenbachia South America bright, but not directly sunny at least 15 °C high water demand poisonous
    dragon tree dracaena tropical Africa and Asia partially shaded to shaded at least 12 to 15 °C keep dry different types
    A leaf Spathiphyllum South America partially shaded to shaded normal room temperature pour copiously air purifying
    elephant foot Beaucarnea recurvata Mexico full sun to shady 18 to 30 °C, cooler in winter moist but not waterlogged Succulent, also called bottle tree
    flamingo flower Anthurium andreanum South America bright, not directly sunny not cooler than 15 °C water moderately very easy to care for
    lucky feather Zamioculcas zamiifolia East Africa bright to semi-shady normal room temperature water moderately very easy to care for
    kentia palm Howea forsteriana Australia sunny to shady normal room temperature water moderately very easy to care for
    monstera Monstera deliciosa Middle and South America sunny to shady normal room temperature water moderately air purifying
    cycad Cycas revoluta South East Asia full sun normal room temperature don't water too much also known as sago palm
    Yucca Palm Yucca elephantipes Central America partially shaded to shaded at least 15 °C pour little tolerates dry indoor air
    miracle shrub Croton petra India bright to semi-shady at least 12 to 15 °C moist but not waterlogged also known as croton, poisonous spurge plant

    Cultivating hydroponic cacti

    Even cacti thrive in hydroponics with no problem, as long as you don't fill the water level above the Optimum mark. After the water level has dropped to "minimum", wait about three to five days before watering again. During the winter months, many species are no longer watered, but only wetted. You should also rinse the nutrient solution out of the pots during the dormant period. Use a substrate that is as large-grained as possible for the cactus culture.

    digression

    Can you also grow vegetables and lettuce in hydroponics?

    In fact, the culture of vegetables, lettuce and herbs in water storage systems is also possible. In many areas of industrial agriculture, only a substrate-free culture is now used, in which the plants grow in a nutrient solution enriched with oxygen. This system is also known as "hydroponics" or "hydro-grow" and can also be used on the home balcony, especially for heavily consuming and thirsty species such as tomatoes. You can purchase special systems and the corresponding nutrient solutions from specialist retailers for this purpose.

    The following video shows how this can work:

    youtube

    What materials do you need for hydroponics?

    However, normal flower pots that you simply fill with expanded clay and water cannot be used for hydroponics. Here the plants would literally suffocate within a very short time, since their roots are in the water and oxygen can no longer reach them. The trick with water storage systems is to separate the substrate and the water supply from each other and only allow the plants to get the moisture they need themselves. The plant roots are not permanently in the water and get enough air. In order for hydroponics to work, you need the materials and accessories described in this section.

    planters

    Classic hydro systems usually consist of two planters: the culture pot contains the clay granules and the plant, and the water level indicator is also placed here. Many hydro culture pots have a special opening for the water level indicator and another for the administration of the nutrient solution - this is also where the roots grow. In principle, a culture pot is a holding system that is placed in another container - a suitable cachepot of the right size. Culture pots come in many different sizes.

    water level indicator

    The water level indicator is indispensable in hydroponics, as it shows the current water requirements of the plants. This makes it easy for the room gardener, because he can see at a glance whether and how much water the plant needs at the moment. The tool reacts to changes in the water level and also shows when it is time to fertilize again. The water level indicator is also available in different sizes, which are selected to match the culture pot.

    plant granules

    Expanded clay is used as plant granules for hydroponics

    Conventional potting soil is an organic material that is created from decay and decomposition processes from dead plant and animal remains. With hydroponics, on the other hand, you use an inorganic substrate that also contains no lime. There are several ways to do this, with expanded clay and other clay granules probably being the most common. These are clay balls (€22.65) which are available in different strengths. Expanded clay absorbs water like a sponge and also has many air pores so that the roots do not suffer from a lack of oxygen. In addition, this material can be cleaned and reused after each repot. In addition to expanded clay, these materials can also be used as a substrate:

    • gravel
    • sand
    • basalt
    • mineral wool

    Which hydro substrate is best suited depends, among other things, on the specific plant. The grain size of the substrate also depends on the species.

    fertilizer

    A special fertilizer is used for hydroponics, which is precisely tailored to the needs of plants cultivated without soil. Normal plant fertilizer is not suitable for this purpose, as it is dosed far too heavily and over-fertilization would therefore occur within a very short time.

    Convert houseplants to hydroponics

    Switching indoor plants that were previously cultivated in soil to hydroponics is a tricky business, because many plants do not tolerate this step. Therefore, it is best to purchase hydroponic plants beforehand or grow self-cut cuttings in expanded clay from the start.

    If you want to convert your soil cultures to hydroponics, it is best to take this step in the spring. At this time, repotting is usually due anyway, and the plants now have the best chance to grow. Proceed as follows:

    1. Lift the plant out of the previous pot.
    2. Carefully remove adhering soil from the root ball.
    3. To do this, you can carefully wash the roots with water.
    4. Then hold the bare-rooted plant in the culture pot.
    5. as well as the water level indicator
    6. Fill the pot with expanded clay
    7. Gently tap the pot on the table to distribute the beads evenly.
    8. refill granulate if necessary
    9. Place the inner pot in a waterproof planter
    10. Now water the plant up to the "minimum" mark.
    11. Water again and again as soon as the gauge falls below "minimum".

    After the change, the plants need a few weeks to grow. It is best to leave the water level indicator at "minimum" or, if you are dealing with rather thirsty plants, up to "optimum". Only in exceptional cases, such as when you are away, should the “maximum” be exhausted.

    Caring for and repotting hydroponics properly

    Hydroponic plants also need to be repotted

    Subsequent care of the hydroponics is uncomplicated: Depending on the type of plant and its nutrient requirements, fertilize it every two to four weeks. To do this, use a special fertilizer for hydroponics, as normal plant fertilizer is dosed too heavily. The water level indicator shows when it's time to water: if it falls below "minimum", you should top up with water. However, do not exhaust the "maximum" and only water as much as absolutely necessary, otherwise rot can occur. If the roots are permanently in the water, this means the death of the houseplant.

    Indoor plants in soil cultivation should not necessarily be repotted every year, but they need a regular substrate exchange - after all, the old soil is used up and has to be replaced with fresh ones. This reason does not apply to hydroponics. Repotting is actually only necessary if the plant has become too big for its container and needs a new one. It might just make sense to remove and replace the top two to four centimeters of expanded clay every year. Over time, these accumulate with nutrient salts and turn an unsightly white color.

    digression

    Can you also grow cuttings in hydroponics?

    If the plant to be grown from the cutting is later to thrive in hydroponics anyway, it makes sense to raise the young plant in a soilless substrate from the start. Take the desired cuttings and plant them in very fine-grained expanded clay. Care for the little plant like any other cutting: Make sure the air is tense by putting a plastic or glass hood over the planter, keep it moist (only moisten the substrate!) and air it daily. As soon as the cutting shows its first growth, repot it in a coarser substrate. Don't make the mistake of trying to root cuttings in a glass of water first. This often goes wrong.

    Alternatives to hydroponics

    In addition to the classic form of hydroponics, there are other systems that work with a water reservoir and are also suitable for indoor plants.

    Planting systems with clay granulate

    For a pot culture with Seamis, for example, you use clay granules that store water and only release it to the plant roots when needed. Here you do not have to wash any soil residue from the roots when switching from soil to granulate culture, but simply replant the plants together with their pot ball. The space left between the root ball and the container wall as well as the surface of the soil ball is filled with granules, which is why the waterproof planter has to be about a third larger than actually needed. Also on the bottom of the pot, first fill a layer of granules up to about a third of the total height of the pot.

    A moisture meter is also used here, but it has to be inserted into the soil ball. The tool does not show the water level, but the degree of moisture penetration of the root ball. Water your houseplant as soon as the moisture meter turns red. As a guide for the amount of water, take about a quarter of the pot volume. Don't be irritated if the gauge doesn't turn blue again immediately after watering: it takes a while. Don't make the mistake of pouring more water than needed.

    Earth culture with water reservoir

    Furthermore, indoor plants can also be cultivated in a soil culture with a water reservoir, whereby special systems are required for this. Otherwise there would be waterlogging and then the plant in question would die. Instead, add a partition between the potting soil, including the plant roots in it, and the bottom of the pot.The water reservoir is below this and keeps the substrate evenly moist, but not wet.

    Indoor plants cultivated in this way only rarely need to be watered. Pour the water over a watering chute on the edge of the pot and not directly onto the ground!

    frequently asked Questions

    Does hydroponics have any disadvantages?

    In fact, hydroponics also has disadvantages. These consist above all in the high susceptibility of the system to errors: A single overdose, for example with nutrient solution or with water, can have devastating consequences and endanger the health of the plant. In addition, it makes sense to check the pH value from time to time so that it always remains in the optimal range.

    What is the white film on the substrate?

    The whitish coating on the clay granules is mineral deposits and not mold at all. Clay is an inorganic material and therefore cannot mold at all. Wash the coating under clear, running water and then let the cleaned granules dry. Then you can use it again and again.

    Is it true that hydroponic vegetables don't taste as good as soil culture ones?

    In fact, the taste of hydroponically grown vegetables and other crops is a subject of constant criticism. Vegetables and herbs would taste bland because they could only develop little aroma. One of the disadvantages of such a system is the uniform taste.

    What do I do with my hydroponic plants when I go on vacation?

    In such a case, you can exceptionally fill the water level to "maximum" and go on holiday with peace of mind. Your indoor plants will be adequately cared for in the next few weeks.

    How do you know if the water level indicator is broken?

    The water level indicator can break or become blocked for various reasons, for example because the plant roots grow into the tool. You don't always notice the lack of functionality. However, there are telltale signs: If the otherwise fairly regular watering rhythm suddenly changes (often always weekly), this could be due to the broken water level indicator.

    tips

    If the chosen planter is too big for the plant or if it is too deep in the water, you can place it on a polystyrene insert and thus get it out of the danger zone.

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