Universal potting soil can be used in pots as well as in the garden. Potting soil is organic material based on peat. It has the property of retaining both moisture and nutrients well. Ideal for plants in a pot. Fertilizer has been added to the potting soil for 6 to 9 weeks, so that plants have a good start. In the garden, the potting soil can be mixed through a border to get a better base.