Keep Me Sane: Reusing Cat Litter Containers Planters! Rather than going out and buying large tubs to keep your plants in, why not repurpose something you have already paid for? Yes, they could be more attractive, but hey, feel free to cover them. Garden Harvester. If you have a large garden, a clean cat litter container (especially the smaller ones), could be excellent to help you bring your harvest in. Compost buckets. This one seems self explanatory.