What happens if I over-fertilise my houseplants?

Over-fertilising is a common houseplant care mistake and can cause more harm than underfeeding. When too much fertiliser is added to the soil, excess mineral salts build up around the roots. These salts can draw moisture away from the roots and lead to nutrient burn, damaging the plant rather than helping it grow.

The most common signs of over-fertilising include brown or crispy leaf tips, yellowing leaves, and browning along the leaf margins. In more severe cases, plants may appear wilted even when the soil is moist, and growth may slow or stop altogether.

If you suspect overfeeding, the best solution is to flush the soil thoroughly with plain water. Slowly run water through the pot several times to help wash excess salts out through the drainage holes. After flushing, allow the soil to drain well and pause fertilising for a few weeks so the plant can recover.

In the future, follow recommended feeding rates and fertilise during active growth periods only. For a deeper understanding of plant nutrients and overfeeding risks, see our guide Houseplant Fertilisers 101: Understanding NPK.