You can fertilize your plants with cinnamon powder pretty easily. This powder is a natural fertilizer because it stimulates root growth, encouraging almost all plant varieties to expand their roots when cinnamon is applied to their soil. You can easily fertilize your plant with cinnamon by sprinkling some powder on your soil and watering your plant as normal. You might want to treat your plants with cinnamon fertilizer periodically as needed, but sparse applications can help your plant get strong.