A typical symptom is when leaves turn yellow. If yellow is not the natural colour of the plants’ leaves, then it may be caused by root level issues like a lack of soil nutrients, incorrect Ph, over-watering or compact soil.
Even though roots are located underground, they still require air to remain healthy and free of fungii and water mould. If the soil does not drain properly, it will retain water and the roots will suffocate or develop a disease. When soil gets too compacted, roots are unable to penetrate the soil, anything that reduces root exploration/activity can limit plant growth.