Hostas are heavy feeders and respond well to fertilizing. Depending on which method you choose, granular or liquid, most people believe in a balanced ratio. Chemical or organic fertilizers are both available. In very rich soil an annual application of leaf mould or garden compost in the autumn is sufficient. A Spring application of 10-10-10 around the base of the plant will give it a good boost. Be careful not to apply fertilizer too near to the crown, in order to prevent leaf burn.