Use what we use! This soil-less potting mix is exactly what we use here at The Country Basket. 
Container plants (hanging baskets, houseplants, flower boxes) and seedlings thrive best when they have plenty of drainage and start out in a sterile environment which is why we recommend using a potting mix (not potting soil). Our potting mix is a combination of Canadian peat moss, perlite, dolomitic lime, calcitic lime, wetting agent and fertilizer.

20 litre bag