Drainage with expanded clay allows water to drain away reliably and quickly, and in a particularly ecological way. Below you will find out exactly what advantages expanded clay has as drainage. We will also explain to you how to use the material correctly.
What are the advantages of drainage with expanded clay?
Expanded clay as drainage prevents waterlogging. The water-permeable and chemically and biologically neutral material is particularly ecological because it is structurally stable and therefore extremely durable. In addition, expanded clay resists pests and fungi, which in turn reduces the risk of infection of the respective plants.
How do I properly use expanded clay as drainage in the plant pot?
First fill the planter with expanded clay and then with soil. How high the layer of clay granules should be depends on the size of the bucket. Also make sure that the grain size of the beads matches the plants. The following applies:
- smaller grain sizes for young plants
- larger grain sizes for larger plants with thicker roots
Grain sizes from approximately5 to 20 mm. are available
Important: Plant pots in outdoor areas should have drainage holes despite drainage with expanded clay. After all, they have to survive heavy rain every now and then.
How high should the drainage layer of expanded clay be?
The drainage layer of expanded clay should bebetween 1 and 15 cm high.
- approx. 1 cm in small flower pots and balcony boxes
- approx. 5 to 15 cm in medium-sized plant pots and massive plant troughs
Note: In tall, slim plant pots, it is recommended to first fill one to two hand-widths of gravel into the container, then, depending on the height of the pot, a 5 to 15 cm high layer of expanded clay and finally the substrate.
Can expanded clay store water as drainage?
Expanded claycannot store waterIt is more the case that excess irrigation water flows away very quickly through a drainage layer made up of the expanded clay balls, causing the potting soil to dry out more quickly. Thirsty plants generally require ashorter watering interval.
Note: The fact that clay granules are sometimes said to have water-storing properties is due to thecapillary effect, which causes the water to rise between the balls. This effect is particularly used in hydroponics.
Tip
Fleece between expanded clay and potting soil for optimal drainage performance
In order to ensure optimal drainage performance over a very long period of time, it is advisable to place a water- and root-permeable fleece between the expanded clay and the potting soil. Such a gardening fleece prevents soil from being washed between the clay balls due to regular watering and the drainage layer from being compacted over time, which would encourage waterlogging again.