For Nettle-leaved bellflower, the ideal soil composition is rich in organic material and well-aerated. This plant thrives in loamy soil, which is a mixture of sand, silt, and clay, enabling proper drainage and nutrient retention. Organic matter, such as compost or well-rotted manure, enhances soil fertility and structure. Incorporating perlite or vermiculite can also improve aeration and water retention, promoting healthier root development.