Yes! You can use Osmocote on succulents and it looks like you have a container of very happy succulents near your window. There is something you need to remember however. Succulents and sedums do not need much fertilizer. A slow release plant food like Osmocote is great because you will avoid the fertilizer burn and damage from a fast acting plant food but I only use half the recommended amount of Osmocote on succulents and only apply it once a year in early summer when the plants are actively growing. I do not recommend feeding succulents or even watering succulents very often during the winter months. (I don't water my jade plant or tender succulents at all during the winter months when they are indoors.) So for your cute container garden wait until June, then add 1/4 of a teaspoon of the Osmocote pellets to the soil and carefully mix it a bit into the rocks. When you water the nutrients will be released very slowly so that your succulents can avoid the fast growth that can cause floppy, soft and misshapen succulents.  Keep growing, Marianne Binetti