A grow bag is useful when you need a movable container, good drainage and seasonal storage. Choose the size and construction from the crop and location before comparing brands.
Start with crop root room
Do not buy one bag size for every crop. Use the container-size guidance in the KAIROS vegetable guide, then choose a bag that provides the required soil volume without becoming too heavy to move.
Fabric vs rigid containers
Fabric grow bags drain freely and fold for storage, but they can dry faster and may need more frequent watering. Rigid containers hold their shape and can be easier to move when they have stable handles.
Handles matter only if the loaded bag can move
Soil and water add significant weight. Handles are useful for repositioning smaller bags; do not assume a large planted bag should be carried just because handles are sewn onto it.
Look at drainage and floor protection together
Free drainage is useful for roots but matters to the surface underneath. On balconies and finished patios, plan for runoff and local building rules before setting up containers.