Mix 20 tablespoons of concrete with water to a creamy mass and pour it into the mould. The mould should then be tapped lightly on the surface to allow air bubbles to rise.
Press the test tubes through the grid into the concrete and let everything dry for about 24 hours.
After the drying time, you can remove the grid and carefully take the silicone insert out of the mould: Loosen the edges and sides from the concrete and take out the casting.
Now also remove the foil with the lettering. If any residue of the Beton-Art liner still remains on the concrete, carefully loosen it with a bamboo skewer.
Finish the plant nursery
Finally, finish the growing station: smooth the edges with sandpaper, colour the lettering with VBS craft paint ivory and decorate the test tubes and the edge of the concrete mould with a cord. 
