Instead of buying expensively: It's best to mix your own potting soil for planting. It's a mix of sand, soil and compost if you make it yourself.
This creates nutrient-poor soil in which young plants can grow well before they can be repotted or planted in the garden. You can easily make the growing soil for young plants yourself. You only need three simple ingredients: sand Aged compost Loose garden soil. The soil mixture is then sterilized in the oven, although various expert websites recommend different temperatures.