A pot puts a boundary around the roots. They cannot simply extend into a neighbouring patch of soil when water or nutrients run short. That makes the container, growing medium and care plan parts of the same system.

Think of a pot as a small reservoir. Its reserve depends on its volume, the mix and the plant using it. Small exposed containers can change temperature and moisture quickly, while larger or sheltered ones may change more slowly. Neither has 'no buffer', and open ground is not an unlimited supply.

Containers can make gardening possible without a border, but plan their filled weight, stability, access and watering before placing them. A balcony or raised support needs an appropriate load assessment; being able to carry an empty pot says little about the completed planting.