Winter is a slow time for lawns in warm temperate, temperate and mediterranean areas. These areas are not good places to apply organic or granular fertilizer in winter. You can use liquid and slow-release fertilisers. However, the effect is usually to lighten the lawn and achieve mild growth.
A granular or organic fertilizer in winter can be used if you live in a tropical or subtropical area to improve the growth of your lawn. It will also help green your lawn nicely. In winter, you can also use slow-release fertilisers like Scotts Lawn Builder. In tropical areas, liquid fertilisers can also be used to green up your lawn in winter.