Providing plant food ensures that plants get the nutrients needed to grow strong. In the case of some flowering plants, plant food also helps the flowers bloom. Three main types of plant food exist: liquid, fertilizer sticks and granular. When feeding a plant, choose the type of food based on the plant's stage of life. Choosing the right plant food for the right stage and plant ensures that the plant absorbs nutrients in the most effective way. Granular foods work best before planting while liquid foods can be used after planting. Fertilizer sticks provide a slow release of nutrients into the soil for up to a year.