A condition where a pot-grown plant's roots have completely filled the container and are circling the pot walls or growing through drainage holes. Causes stress, wilting, and poor growth. Requires repotting into a larger container.
When a plant becomes root bound, its roots circle continuously around the inside of the pot, forming a dense, matted root ball. This prevents proper water drainage and nutrient absorption, even when you water regularly. You'll notice symptoms like yellowing leaves, wilting despite wet soil, and slower growth during spring and summer when plants should be thriving.
Root bound plants are particularly problematic in Australia's warm climate zones, where containerised plants dry out faster anyway. The compressed root system exacerbates water stress. To check if your plant is root bound, tip it from its pot and inspect the roots—if they're white and spiralling densely, it's time to repot.
Repot into a container only 2-5cm larger in diameter, using quality potting mix from Bunnings or your local nursery. Autumn (March-May) is ideal for repotting in most Australian zones, as plants aren't in peak growth. For vigorous growers like citrus or hibiscus in tropical zones, you may need to repot annually. Gently tease apart the root ball before planting to encourage outward growth. This prevents your container garden becoming permanently stunted.