Expanded clay is the prime example of successful cooperation between man and nature. This guide explains how expanded clay is created and provides important information about its properties. Explore the wide range of possible uses for gardening, plant care and house construction. Here you can find out where you can buy the beneficial natural material, including an informative price comparison.

Expanded clay has many uses in the garden and house

Table of Contents

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  1. the essentials in brief
  2. What is expanded clay?
  3. What to do?
  4. Expanded clay use garden
  5. Expanded clay plant care instructions
  6. Buy expanded clay
  7. Expanded clay reduces potting soil consumption
  8. frequently asked Questions

    9. the essentials in brief

    • Expanded clay (€19.73) is granulated, fired clay that expands many times over to small balls at 1200° Celsius.
    • Expanded clay is germ-free, non-rotting, frost-resistant, dimensionally stable, fire-resistant and insulating. Expanded clay pebbles have a closed-cell core with a porous surface so that water is absorbed and drained, but not absorbed.
    • Expanded clay is to be used as a natural product for garden and plant care as well as in ecological house construction.

    What is expanded clay?

    Expanded clay consists of low-lime clay and many, many air bubbles

    The starting material for expanded clay is low-lime clay with organic components and no chemical additives. For the production, mined clay is ground and fired in the oven at 1200° Celsius. During this process, the organic components in the clay balls burn, causing them to expand many times over. The result is a light and round shaped granulate, aptly named expanded clay or clay granules. Expanded clay is characterized by the following properties:

    • sterile: does not mold
    • neutral: no effect on pH
    • structurally stable: pressure resistant, prevents soil compaction and waterlogging
    • weather resistant: usable outdoors and indoors
    • indestructible: inorganic, does not decompose
    • fireproof: non-flammable
    • insulating: good sound insulation, average thermal insulation (0.10-0.16 W/mK)
    • environmentally friendly: contains no chemical additives

    The firing process produces expanded clay balls with a closed-pore core surrounded by a sintered, fine-grained surface. This process has a decisive influence on the behavior in water. True, expanded clay absorbs moisture in its shell. However, the closed-pore core prevents water from being absorbed.

    Expanded clay was invented by S. Hayde in the USA at the beginning of the 20th century, to which the American name Haydite refers. The international brand name for expanded clay is Leca, an abbreviation for lightweight expanded clay aggregates. Rarer name is keramsite.

    What can you do with expanded clay? - Overview

    Sensitized environmental awareness has brought expanded clay into focus for natural garden and plant care. In ecological house construction, the niche product is at the beginning of a steep career as a natural building material. In view of the impressive properties of the clay granules, the following possible uses have emerged so far:

    garden plant care house building
    soil improvement drainage material building material
    Drainage substrate raised bed hydroponics insulation
    tree substrate substrate component bricks
    light grit increase in humidity sound insulation fill
    winter grit mulch

    Are you consulting this guide because you want to use expanded clay as an innovative building material? Then we recommend that you read numerous specialist articles at Hausjournal.net. Here you can read how you can use the special advantages of expanded clay, for example for thermal insulation as fill or as a lightweight aggregate for bricks or cement. The possible uses are examined in detail, including their advantages and disadvantages.

    digression

    Expanded clay optimizes green roofs

    Expanded clay is also used for green roofs

    In ecological house construction, expanded clay perfects the substrate for green roofs. On the roof, the substrate acts as a rooting layer for the planting and drainage for water drainage at the same time. For this purpose, nutritious topsoil enriched with expanded clay is broken. For perfect functioning, the proportion of topsoil should be reduced from top to bottom in order to optimize the drainage effect. Furthermore, it is recommended to thin the heavily loamy substrate with fine-grained sand for vital growth of the special green roof plants.

    Using expanded clay in the garden - tips & tricks

    Hobby gardeners who are close to nature have discovered expanded clay as the ideal problem solver for a wide range of tasks. Thanks to the light, airy, water-conducting clay balls, the framework conditions for plant growth can be improved in harmony with nature. What is indicated in the table above is explained in more detail in the following sections.

    soil improvement

    Garden soil with a high proportion of loam and clay tends to become seriously compacted. Harmful waterlogging occurs because the rainwater does not run off or only runs off slowly. Vegetable plants, flowers, perennials and shrubs suffer from permanently wet roots and die. By mixing clay granules under heavy garden soil, you eliminate the problem. How to improve soil with expanded clay:

    1. Dig up bed soil two spade-deep (optional seven more)
    2. Work in 3 liters of mature compost per m² of bed area
    3. Mix in a handful of expanded clay per liter of compost
    4. flatten improved garden soil with the rake

    Please use expanded clay with a medium grain size of 4 to 10 mm to improve the soil. Finer grain sizes harbor the risk of capping and thus undermine the desired loosening and aeration effect in the soil.

    drainage substrate in the raised bed

    Expanded clay is also good for raised beds

    Filling a raised bed properly requires a good deal of expertise and even more time. Understandably, hobby gardeners are specifically looking for an uncomplicated solution. A clever move is the use of a ready-made raised bed filler. The Liapor company is in the lead here with a high-quality special product based on expanded clay. Thats how it works:

    1. Cover the ground in the raised bed with rabbit wire to prevent voles
    2. Place a 30 to 50 cm layer of raised bed filler on top
    3. cover with a drainage fleece
    4. Fill in 15 to 25 cm of mature, sieved compost as a planting layer

    With the Liapor raised bed filler you are using a natural, balanced base and drainage material that gives your plants a free hand. Waterlogging, root rot or mold have little chance of impairing vital growth and bountiful harvests. Thanks to the low weight of expanded clay, back-friendly gardening starts with filling the raised bed.

    tree substrate

    Trees go through a delicate phase in the first two years. In order for underground and above-ground growth to proceed smoothly, the best possible framework conditions in the soil are important. With expanded clay as an additive in the tree substrate, you effectively prevent the negative effects of waterlogging on the day of planting. The high firing temperature in the manufacturing process makes expanded clay balls extremely resistant. Extreme loads caused by frequent changes between frost and thaw do not prevent clay granules from continuously guaranteeing the best water permeability and permanent soil aeration.

    light grit

    Broken expanded clay is very popular in creative gardening and landscaping. In contrast to clay pellets, broken expanded clay fragments already interlock when applied to the substrate. Furthermore, expanded clay as light chippings is frost-resistant, non-rotting and moisture-regulating. On the porous surface, the granulate only absorbs moisture for a short time. Without swelling, excess water is quickly channeled into deeper soil layers for an effective drainage effect. Thanks to a dry bulk density of around 0.5 t/m³, expanded clay is a real lightweight compared to gravel and conventional grit.

    These properties make broken expanded clay the ideal substructure for terraces, garden paths and seating areas. For this purpose, fine-grained expanded clay granulate is applied as a fill about 4 centimeters high.

    winter grit

    Broken expanded clay is recommended for use as an environmentally friendly winter grit to prevent slipping. This variant reduces the purchase price by up to 50 percent. Furthermore, the sharp-edged clay granules are much better than beads for sprinkling icy garden paths and driveways to prevent them from slipping.

    Expanded clay in plant care - instructions for beginners

    Once hobby gardeners have learned to appreciate its advantages, they no longer want to do without expanded clay in plant care. The following short instructions will show you how to get the benefits of this natural product:

    drainage

    Expanded clay is filled in the flower pot as a drainage layer as the bottom layer

    Expanded clay deserves the title excellent as drainage. Because the fired clay balls don't absorb the water but pass it on, waterlogging in boxes, tubs and flower pots is a thing of the past. Fill in a layer of expanded clay about 5 centimeters high over the openings in the floor, which you first cover with a piece of potsherds. Excess irrigation water and rainwater can now drain away quickly. Use drainage fleece to prevent crumbs of earth from cheating between the expanded clay balls. This is an air- and water-permeable fabric that you spread between the substrate and the drainage.

    hydroponics

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    The good clay for magnificent indoor plants comes in the form of expanded clay. By potting your soil-bound plants in expanded clay, guesswork about proper watering and nutrient supply is a thing of the past. Sophisticated orchids reside in expanded clay, while the beauties of the rainforest wallow in an opulent rush of flowers. The keyword for these motivating, gardening successes is hydroponics. According to this principle, you can also plant large tubs with expanded clay. You need a waterproof planter with a special inner pot, expanded clay, water level indicator and nutrient solution. How to proceed correctly step by step:

    1. Water expanded clay for 12 to 24 hours
    2. Unpot the plant and shake off the soil
    3. Rinse the last remains of substrate from the root ball
    4. Place bare plant roots in the middle of the special inner pot
    5. Position the water level indicator in the inner pot so that it is easy to read
    6. Fill in expanded clay
    7. Tap the inner pot lightly on the table to distribute the clay beads evenly
    8. Place the pot in the waterproof planter

    For the first watering, fill in room-warm water up to level 1 of the water level indicator. Expanded clay uses capillary force to direct water to the roots. In the future you can read from the display when you should water the plant again. Because hydroponic plants cannot live on water alone, a special nutrient solution ensures that they are supplied with all the important nutrients.

    substrate component

    The joy of inexpensive potting soil does not last long, because compacted substrate in tubs and balcony boxes chokes off the air for plant roots. This shortcoming does not mean that you will have to do without special offers in the garden center or hardware store in the future. As soon as you mix a little expanded clay with the soil, an airy, loose permeability is ensured in the substrate. Fine clay granules with a grain size of 1 to 4 mm are well suited. Because expanded clay is structurally stable and pressure-resistant, the substrate cannot collapse even after a long period of time. Plants and nature are completely happy when you enhance peat-free potting soil with expanded clay.

    Substrates enriched with expanded clay are airy, loose and permeable

    increase in humidity

    At the start of the heating season, tropical indoor plants rebel against the dry indoor air. Almost all exotic potted flowers depend on a humidity level of more than 50 percent. If the value falls below this mark, growth depression, leaf and flower fall are inevitable. This is where expanded clay comes into play to regulate the air in the room without a mechanical humidifier. It's so easy:

    1. Fill saucers from pots or buckets with expanded clay
    2. Place the vessel on the expanded clay
    3. Pour water into the saucer

    The water evaporates over the globular, rough surface and rises as steam. In this way, a microclimate with increased humidity is created in the immediate vicinity of the plant.

    mulch

    When it comes to caring for majestic potted plants and large flower boxes (€16.99), weed control is a tiresome subject. Primarily woody plants gradually bare at the base. The exposed soil surface attracts weeds that spoil the well-groomed appearance. Annoying weeding is the annoying result. It doesn't have to come to that if the plants have a mulch layer made of expanded clay at their feet. With a layer height of about 2 centimeters, clay granules suppress the growth of weeds without impeding the water and nutrient supply.

    tips

    Contrary to popular belief, expanded clay does not act as a water reservoir. Consequently, clay granules do not prolong watering intervals when used as an additive in potting soil. The test of the example provides the proof. Put a handful of expanded clay in a glass with water. The beads are still floating on the surface of the water for hours and are not soaking up water.

    Buy expanded clay - shopping sources with price comparison

    Expanded clay prices vary greatly depending on the seller

    Expanded clay had a niche existence for a long time and was difficult to find on the market. Ever since word got around about the environmentally friendly properties, more and more hardware stores are including the product in their range. We looked around the market to see what was on offer and the price structure. The following overview lists purchasing sources with price comparison:

    providers Price 2-2.5L price 5 l 10L 50L
    bauhaus 2.95 euros EUR 10.95 EUR 21.90 no offers
    obi 2.69 euros EUR 4.99 €5.99 18.99 EUR
    toom 4.49 euros 6.49 euros 9.49 euros no offers
    Hornbach 2.95 euros EUR 6.95 9.99 EUR (15 l) no offers

    If you want to buy cheap expanded clay in a 50 l sack, you will rarely find it in well-known hardware stores. Here the offers usually end at 10 l. Larger containers can be found on Amazon from EUR 21.90 per 50 l for fine, medium or coarse grains. Hornbach is an exemplary supplier for hobby gardeners with a great need for expanded clay. Here you get a pallet with 1,260 liters (42 x 30 l) for the price of 605 euros with free shipping.

    Please note that this price comparison is a snapshot that does not claim to be representative. As with all products for gardening, plant care and home construction, supply and demand determine the price.

    Bargain foxes buy expanded clay in specialist shops

    When hobby gardeners want to buy a large amount of expanded clay cheaply, the focus is on the specialist trade. Specialist companies for expanded clay fill as a building material usually offer suitable products for garden and plant care. The Liapor company is in the lead with the “Liadrain” brand, an expanded clay suitable for plants as a substrate component for balcony and terrace greening and for filling raised beds. At Liapor-shop.de you can purchase a 50-liter sack for an inexpensive EUR 9.58 plus shipping costs.

    background

    Seramis is not expanded clay

    Seramis and expanded clay do not have the same properties

    A widespread lack of information about clay granules causes fatal failures in plant care. Many indoor gardeners are under the misconception that seramis and expanded clay are identical. In fact, there is a major difference between the two materials. Seramis plant granules contain clay beads that have undergone a special process to increase the pore volume. As a result, the beads soak up water, like a sponge. This high water retention is beneficial for soil-bound plants but unsuitable for hydroponics. In contrast, expanded clay does not store moisture, but operates with ideal water and air flow, which is vital for all hydroponic plants. As a result, Seramis plant granules are not an alternative to expanded clay, but score with other advantages.

    Expanded clay reduces potting soil consumption

    The most beautiful bedding and balcony flowers depend on a special substrate. So that geraniums, petunias or azaleas bloom lavishly, hobby gardeners grudgingly dig deep into their pockets to buy high-quality branded products. With expanded clay, you put the brakes on consumption and costs. The one-off investment in an adequate supply is worthwhile, because expanded clay can be used again and again and does not go limp even after several years. This is how the gardening trick works:

    1. Cover openings in the bottom with arched potsherds
    2. Fill buckets, pots or flower boxes (€16.99) halfway up with expanded clay (fine to medium grain)
    3. Cover expanded clay layer with drainage fleece
    4. Fill in special potting soil and plant

    Instead of drainage fleece, you can use disused nylon stockings, which also reduces costs. Stuff each stocking with expanded clay and tie a knot at the top. In this way, the clay granules are spared from soiling from the substrate, can be easily lifted out of the planter at the end of the season and reused next year.

    frequently asked Questions

    Is expanded clay toxic?

    Expanded clay is a purely natural product with no chemical additives. The manufacturing process is limited to crushing and heating clay. For this reason, with expanded clay you are holding a completely harmless product that fulfills a wide range of tasks in natural gardens and environmentally friendly house building.

    Is there an alternative to expanded clay?

    Perlites are often used as a substitute for expanded clay

    Perlite is extracted from obsidian, a volcanic rock glass. The natural material goes through a similar manufacturing process as expanded clay and has analogous properties and uses. The only outstanding difference is the color of the beads. Perlite is white to off-white and resembles popcorn. In contrast, expanded clay balls are reddish brown, light brown or dark brown in colour. In a direct price comparison, Perlite scores points with a price that is up to 50 percent cheaper than expanded clay.

    In which grain sizes can expanded clay be bought?

    Expanded clay with a fine grain size of 1 to 4 mm is suitable as a substrate additive for indoor and balcony plants. Furthermore, fine-grained clay granules are used in house construction as fill for thermal insulation or soundproofing. With a medium grain size of 4 to 10 mm, expanded clay is used for hydroponics, as drainage in planters and for soil improvement. With a coarse grain size of 10 to 20 mm, expanded clay is often used as a building material in ecological house construction. In addition, coarse-grained clay granules are useful as drainage for large potted plants.

    Can the advantages of expanded clay be used for a beautiful lawn on heavy clay soil?

    If you create a new lawn on heavy clay soil, expanded clay as an additive provides valuable protection against waterlogging. For this purpose, work a layer of 5 to 10 centimeters of expanded clay into the earth when you create the rough subgrade. You can rehabilitate old, mossy lawns with expanded clay and breathe new life into them. This is achieved with narrow slits 3 centimeters wide and 5 centimeters deep, which you pierce in the lawn at intervals of 60 centimetres. Then fill the small furrows with fine-grain expanded clay, sprinkle a compost-sand mix over them and roll the lawn.

    Is expanded clay suitable for growing young plants in hydroponics?

    In fact, you can place hydroponic seedlings in expanded clay from day one. Use a 1-4mm grit to help the delicate roots take root quickly. Before the first use, the clay granulate is thoroughly soaked. Then fill the seed pot halfway with expanded clay. Place the young plant on the substrate, distribute existing roots evenly and fill in the remaining clay granules. now you can place the pot in a watertight vessel and water to the minimum level. It is important to note that there must be no soil residue on the plant.

    Can expanded clay be used as a filter medium for the garden kingdom?

    The use of expanded clay as a filter medium is a controversial topic among experienced pond owners. The porous surface of the clay balls is seen as critical. Bacteria, algae and dirt accumulate here over time, which can be detrimental to the health of fish. For safe use in the pond filter, it should be ensured that expanded clay is regularly and thoroughly cleaned of deposits.

    In what ratio should expanded clay be mixed with soil for optimal growth?

    If you mix expanded clay with soil in a ratio of 1:9, you effectively prevent growth disorders. With this mixing ratio you give the soil a permanent loosening and oxygen supply. A higher proportion of expanded clay makes the soil too permeable, which is just as unfavorable for the plants as a structure that is too solid.

    What is a drainage fleece?

    A drainage fleece has the task of preventing the mixing of two different soil layers. This is a special fabric that is water and air permeable. In combination with expanded clay in plant care, the drainage fleece prevents soil from settling between the clay balls. If you use clay granules as light grit in the garden, a drainage fleece also takes over the task of weed fleece.

    tips

    As an environmentally friendly natural material, expanded clay can be disposed of in the organic waste bin or in the compost. In view of its multiple advantages, it is advisable to recycle valuable clay granules, comparable to lava granules. Simply rinse with clear water and expanded clay is in top form for repeated use.

Category:

Indoor plants