To ensure healthy growth, the soil composition for Large-leaved avens should be rich, loamy, and well-draining. Loamy soil is an ideal mix of sand, silt, and clay and provides a balanced medium for the plant's roots. It ensures good nutrient retention while allowing excess water to drain away effectively. By using a soil mix that contains a good proportion of organic matter, such as compost or leaf mold, you can further enhance its nutrient content and structure, creating an optimal environment for Large-leaved avens to thrive.