PH
When a plant remains in a container for a long time, roots can reach the pot walls and begin growing around the available space.
Eventually, a dense root system may occupy much of the container. This condition is commonly described as being root-bound or pot-bound.
Water can become harder to manage, and plant growth may be affected when roots become severely congested.
A plant can look relatively normal above the soil while an entirely different situation is developing inside its pot.
© Royal Horticultural Society