The best time to fertilize varies depending on the plant species and the climate you live in. Generally, the start of the growing season, just as plants are entering a growth spurt, is ideal. This typically occurs in the early spring for many plants. However, it can also be beneficial to apply fertilizer 6 24 24 when plants are setting buds and when they’re developing fruit or flowers. Make sure to avoid fertilizing during the late fall or winter when many plants are dormant.