As soon as the bale of a plant is completely penetrated by roots it is time to give it more space. The same applies when roots begin to grow out of the pot. The new vessel should be three to four centimetres taller. If it is too large, the plant concentrates on rather setting up new roots than on the desired flower and shoot formation. White sites at the surface of the soil are a sign that the plant needs fresh soil. This is a result from hard water or too much fertiliser.