Agave plants typically do not require a lot of fertilization, and in fact, too much fertilizer can be harmful to their health. However, a small amount of slow-release fertilizer can be added to the soil around the base of the plant once per year in the spring to help promote healthy growth. It's important to choose a fertilizer that is formulated specifically for succulent plants and to follow the manufacturer's instructions for application rates. Additionally, during the growing season, top-dressing the soil with compost can also be beneficial. It's important to avoid getting any fertilizer directly on the leaves of the plant, as this can cause damage.