Repurposing old potting mix can be good for the plant and the planet – but how do you know whether to re-use or replace?
The problem
Repotting often leaves you staring at a pile of old potting mix and wondering: “Should it go in the bin, the garden, or back into another pot?” Reusing soil feels thrifty and sustainable, but tired potting mix can contain compacted roots, harbour pests and be drained of nutrients. So how do you know when to refresh and when to replace?
The hack
Old soil isn’t always bad soil. Most potting mixes lose structure and nutrition over time, but they can often be revived with a bit of care. If the mix smells musty, contains mould or has signs of fungus gnats, it’s best to discard it. But if it’s dry, healthy and crumbly, you can usually bring it back to life.
