When sowingseeds, the growing medium is important. Ordinary garden soil is no good as it usually harbours weeds and its drainage qualities are often poor.
It is best to buy pre-packed potting soil from a reputable garden centre or nursery.If you want to prepare your own potting soil, the best mix is two parts loamy soil to one part acid compost and one part coarse sand. To each 10-litre bucketful, add a tablespoon of superphosphate or bone meal, mixing it in well.
(Although imported peat moss has traditionally been used in potting mix and to add acidity to soil, it is not an environmentally sound choice. Substitute peat moss with acid compost, which is readily available from good nurseries and plant centres.)