Yes! Osmocote is great for houseplants as it is a slow release fertilizer and will not burn the tips of the leaves. For potted, indoor plants use half as much Osmocote as you would for outdoor plants following the instructions on the label. (If y0ur fig is in a 5 gallon container, one capful or 3 tablespoons would be about right.) This is because indoor plants get less sunlight and grow more slowly than outdoor plants so they do not require as much feeding.  Work the product into the top inch of soil being careful not to disturb any roots. You should fertilize during the growing season so spring or summer. The best part about using Osmocote is that it will continue to feed your houseplants for 6 months. It also has all the micronutrients that any plant would need along with the big three nutrients nitrogen, phosphate and potash. Fiddle leaf figs can grow quite large and look so much healthier when fertilized. Keep growing, Marianne Binetti