8. Self-Watering Sub-Irrigation Mason Jars
One of the biggest challenges of growing herbs in mason jars is managing moisture levels. Because these jars do not have drainage holes, it is easy to overwater them, leading to root rot, or underwater them, causing the herbs to wilt. A self-watering sub-irrigation system solves this problem completely, turning your mason jars into smart, low-maintenance planters that deliver water directly to the roots as needed.
To create a self-watering jar, you will need to cut a plastic bottle or use a small net cup that fits snugly inside the mouth of the mason jar. Thread a thick piece of cotton utility wick, acrylic yarn, or strip of cotton fabric through the bottom of the cup, leaving several inches dangling down into the bottom of the glass jar. Fill the bottom of the jar with water, and fill the upper cup with potting soil and your herb plant, ensuring the wick is embedded in the soil. The wick will draw moisture upward from the water reservoir into the soil via capillary action, keeping the soil perfectly damp but never soggy. This system is perfect for thirsty herbs like basil and mint.