Salt Leaching Methods: Tips On Leaching Indoor Plants

Watering An Indoor Yellow Potted Plant
(Image credit: ronstik)

Potted plants have only so much soil to work with, which means they need to be fertilized. This also means, unfortunately, that extra, unabsorbed minerals in the fertilizer remain in the soil, potentially leading to nasty buildup that can harm your plant. Luckily, there’s an easy process for getting rid of this buildup, called leaching. Indoor plants should be leached regularly to keep their soil clear. Keep reading to learn more about how to leach a houseplant.

Reasons for Leaching Houseplants

The minerals you’re getting rid of are called salts. They were dissolved in water and left behind when the water evaporated. You might see them in a white buildup on the surface of your plant’s soil or around the pot’s drainage holes. This is evidence that there are even more salts in the soil. As these salts build up, plants have a harder time drawing up water. This can lead to browned, wilted, or lost leaves and slowed growth. If too many salts build up, the plant will draw moisture from its own root tips and die. For this reason, knowing how to leach a houseplant is important for its overall health.

Tips for Leaching Salt from Soil

Leaching indoor plants sounds intimidating but it doesn’t need to be. In fact, leaching salt from soil is easy. If you see visible white buildup on the surface of the soil, gently remove it, taking care not to take away more than ¼ inch (0.5 cm.) of soil. Next, take your plant outside or put it in a sink or bathtub -- anywhere lots of water will be able to drain freely. Then, slowly pour warm water over the soil, making sure it doesn’t overflow the rim of the pot. Pour twice as much water as the plant container would hold. For example, for a half gallon pot (2 L.), slowly pour a gallon (4 L.) of water. The water will absorb the salts and carry them away. Leaching houseplants every four to six months will make for clear soil and healthy plants.

Liz Baessler
Senior Editor

The only child of a horticulturist and an English teacher, Liz Baessler was destined to become a gardening editor. She has been with Gardening Know how since 2015, and a Senior Editor since 2020. She holds a BA in English from Brandeis University and an MA in English from the University of Geneva, Switzerland. After years of gardening in containers and community garden plots, she finally has a backyard of her own, which she is systematically filling with vegetables and flowers.