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Many of the orchid species that come from the tropics and subtropics do not grow in the ground, but rather cling to the crowns of the jungle trees with their roots. The roots of these so-called epiphytes or epiphytes need more oxygen and air than the roots of "normal" plants that grow in soil. In conventional potting soil, these orchids would quickly rot due to lack of oxygen and moisture. Therefore, a culture without soil - for example in a glass - is preferable.


Advantages of soil-free cultivation in orchids

Epiphytic Orchids-d. H. those that perch on trees etc. in their natural environment - don't need soil anyway. These species can be cultivated in pine bark, coconut fibre, white peat or seramis or a mixture or without any substrate at all. Only terrestrial orchids such as cymbids or venus slipper orchids need a soil mixture of pine bark and seed or young plant soil. The orchid soil should be as coarse as possible, because the substrate serves less as a water and nutrient storage, but gives the plant support and ensures sufficient air in the pot through the large gaps between the substrate chunks. However, since water and nutrients are only added by watering, growing in substrate is not really necessary.

The completely substrate-free culture offers interesting advantages:

  • always enough light and air at the roots
  • The water requirement of the plant is immediately visible: do not water when the roots are green
  • Watering only necessary for white roots
  • substrate-free culture very well suited for allergy sufferers or sensitive people
  • as there are often fungal spores and other allergens in flower substrates
  • Orchid culture without soil at the same time without allergens
  • Pests and diseases that are often introduced in ready-made orchid soil
  • soilless culture in the jar is an interesting eye-catcher


What are the possibilities of growing orchids without soil?

Apart from growing without substrate in a jar - which is not suitable for all types of orchids - there are other ways of growing the beautiful flowers without soil. Some species prefer certain forms: while terrestrial orchids, for example, are not happy in a completely soil-free culture in a glass, epiphytic species feel particularly comfortable in block culture. Before you decide on a form of cultivation, it is best to take a look at the specific needs of the selected orchid species: they can differ greatly from one another.


Hydroponics works without any substrate, instead expanded clay or clay granules are used to stabilize the plant in the pot. However, this form of plant culture is only suitable to a limited extent for orchids, because the roots do not grow in water. Instead, they rot if they are constantly waterlogged. If you still want to grow your orchids hydroponically, you should follow these tips.

  • Always fill the water level indicator only to "optimum", never to "maximum".
  • Orchid roots should never reach into the backwater
  • Immediately remove and wash damaged roots. Wash expanded clay thoroughly
  • only use very coarse expanded clay - because of the better permeability
  • Halve the dose with liquid fertilizer, but fertilize accordingly more frequently
  • wash the substrate carefully when moving - risk of rotting

block culture

The block culture does not require any plant pots or soil. It is particularly suitable for epiphytic orchids such as the popular Phalaenopsis. To do this, the orchids are tied to pieces of wood (e.g. oak, beech or coniferous wood with solid bark). A special plant material, usually sphagnum moss (also known as swamp moss), is required for binding. The plants themselves are secured with copper wire, soft tie wire, or a cut nylon stocking. Be very careful when untying, under no circumstances should plant parts or roots be crushed. However, never let the roots or even the plants themselves simply hang loose, as this will cause the roots to detach from their substrate and eventually die.

Tip: The block culture only succeeds with really high humidity, as is possible in a greenhouse, in a display case or in a terrarium. Tied orchids are also only fertilized with half the recommended concentration, but more frequently.

Convert orchids to block culture - this is how it works:

If you want to convert your epiphytic orchids to the more natural block culture, the best way to do this is as outlined below.

  • Prepare the base

Attach a wire hook to the top or center of an appropriately sized piece of cork or wood. Then evenly cover them with moist sphagnum.

  • Prepare the orchid

First, remove old roots and leaves from the orchid and carefully rinse out any remains of the substrate. Now place the roots on the base and spread them evenly.

  • Cover the roots

Cover the roots with moist sphagnum to just below the root collar. You can let very long roots stick out to the side.

  • Tie orchid

Now tie everything together tightly, but not too tightly, with binding wire. Start at the root neck. Finally, cut the wire and knot it carefully.

Tip: Orchids grown in pots are best switched to block culture in the spring, although it is better to place very large plants in baskets: these specimens are at risk because the roots naturally dry out easily in block culture. If you spray the plant and roots more often, the transition will be easier and the orchid will adapt more easily.

Orchids in the jar

The completely substrate-free culture in the glass is very pretty to look at and especially suitable for many epiphytic species. To do this, place the plant with bare roots in a tall glass with a wide opening - hyacinth glasses in particular are just right for this purpose. When switching from pot to glass culture, make sure that there are no longer any substrate residues attached to the roots: these only promote rot, which is why the roots must be cleaned thoroughly. To do this, rinse the roots with running, lukewarm water and be careful not to kink or otherwise injure the sensitive parts of the plant. After inserting, pour about a centimeter of rainwater into the glass so that the roots hang slightly in the water. They soak quickly and turn green.

Tip: The jar is the right size when the orchid sits firmly in it without wobbling, even without a supporting substrate. If the orchid is still too loose, it is better to choose a smaller container.

orchid species

Which orchid species are suitable for cultivation in glass?

Epiphytic growing orchids are particularly suitable for a substrate-free culture in the glass. These plants, also known as epiphytes, come primarily from the warm and humid tropical or subtropical rain forests. Their living conditions in the room should be designed accordingly: warm, humid and bright - the latter, however, not necessarily directly sunny. The following species are perfect for glass culture.


  • from Southeast Asia, up to 50 centimeters high, very floriferous and with a long flowering period


  • from Southeast Asia, up to 40 centimeters high, very long flowering period

Asco center

  • from Southeast Asia, up to 40 centimeters high, floriferous, forms clusters of flowers in intensive colours


  • from East Asia, up to 15 centimeters high, small, pretty flowers, difficult to cultivate

Tip: Choose orchids that tend to stay small or grow slowly for cultivation in a glass: species that grow very large will not find support in this form and often have to be tied up or supported with the help of a stick. In addition, you can only choose species whose roots are not sensitive to light.


Caring for orchids in the glass properly - this is how it works:

So that you can enjoy the magnificent flowers of the orchids for a long time, species-appropriate care is immensely important. Basically, orchids are not necessarily easy to care for, although the requirements can vary greatly. Some types of orchids, such as many Phalaenopsis hybrids, are considered to be very easy to care for and often thrive without any problems on the windowsill - provided they have sufficient (but not too much!) light, are watered correctly and fertilized sufficiently. Since tropical orchids such as Vanda and the closely related species Aerides, Ascocentrum and Neofinetia in particular are cultivated in glass, the following information applies to them. Other orchids have different needs.


location and light

Like all plants, orchids need light to carry out photosynthesis. Most species that grow in the light shade of other jungle plants do not tolerate direct sun. As plants of the tropics and subtropics, however, they are used to almost always getting the same number of hours of light. The day length near the equator is about 12 hours all year round - in our country, on the other hand, orchids get up to 16 hours of light in summer and often only two hours in winter. Additional light is therefore usually necessary in dark locations and during the winter months so that the plants thrive. Conversely, excessive light intensity can also be harmful to the plants: direct sunlight can burn the sensitive leaves, especially in spring and summer.


When cultivating without substrate in a glass, you must ensure that the orchids do not dry out. Healthy plants have firm, leathery leaves with a shiny surface. However, if the plant is too dry, the leaf surface will become dull and sallow, and the leaves will pucker and be soft and pliable. Pay particular attention to these points when supplying water.

  • always leave about a centimeter of water in the glass
  • Empty and refill water weekly
  • Do not water orchids cultivated without a substrate
  • but instead dip or spray
  • Spray orchids daily with room temperature water
  • before spraying again, the roots should be dry
  • green roots don't need water yet
  • use only lime-free or decalcified water
  • Keep humidity constantly high
  • No water should remain in the leaf axils or in the heart at the end of the shoot
  • both lead to rot
  • always spray in the morning, then the plant can dry off during the day
  • Flowers must not get wet

Tip: The biggest problem when caring for Vandeen and its relatives on the windowsill is dry air and, with it, slow drying of the plant. As an emergency measure in case of drought, soak the roots in water for two hours until they are soaked with moisture.


In a substrate-less culture, the orchids should be fertilized every two weeks between June and November. In December and January, on the other hand, no fertilizer is used. Provide the plant with nutrients as follows.

  • Soak roots in a liquid fertilizer solution for ten minutes
  • Plant should become soaked with liquid
  • only use liquid orchid fertilizer
  • however, only mix half the concentration recommended for potted orchids
  • otherwise the salinity is too high for the roots

Tip: Do not choose indoor plant fertilizer for your orchids, but always a special orchid fertilizer. In addition to the nutrients, it contains all the important trace elements.

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