Fabric grow bag

A fabric grow bag is a container made from a woven or felt-like material rather than rigid plastic, ceramic or metal. Air passes through the fabric walls, which prunes roots naturally when they reach the edge, encouraging a denser, more branched root system instead of the tight circling roots that can develop in a solid-walled pot. Because the whole surface drains and breathes, waterlogging and root rot are less common than in solid containers.

Grow bags are especially useful on balconies because they are lightweight even in large sizes, fold flat for storage over winter, and are usually far cheaper than an equivalent ceramic planter. Their downside is that they dry out faster than plastic or ceramic since moisture escapes through the fabric, so plants in bags often need more frequent watering, particularly in full sun or wind.

When choosing a size, go larger than you think for fruiting vegetables like tomatoes or peppers, since bags lose some usable volume to the fabric shape. Look for reinforced handles if you will need to move the bag, and reasonably thick fabric that will survive more than one season outdoors. A common mistake is placing a bag directly on a hot, dark balcony floor, which speeds up drying even further, so setting it on a stand or tray helps.