So far, you have not used expanded clay ? See what your plants have lost! Loosens and aerates the soil Provides air access to the root system A layer of expanded clay added to the bottom of the pot (2-3cm) prevents the plant from overflowing and does not lead to root rot Urbi DUC400 Longitudinal Flower Pot with Insert + Expanded Clay 1l - White The set includes: Urbi Longitudinal Flower Pot DUC400 x1