Expanding Soil Disc, Seed Starting Potting Mix, Soil Disc Contains Worm Castings & Water-retaining Crystals, Soil Mix, Potting Mix Urban Leaf helps city dwellers fall in love with gardening, & be a part of a food system that puts the planet & its people first. We got out start in 2017 off the back of a crowdfunding campaign called The World’s Smallest Garden on Kickstarter. The support of our community is what has allowed us to continue growing ever since! Just add 3/4 water product to produce a hassle-free seed-starting potting mix. These coir-based dehydrated & expanding soil discs also contain worm castings (plant food) & water-retaining crystals. These are exactly the same as the soil discs used in our Garden Trio kits, so if you’re looking for a ‘refill’ for one of the wooden planters, then this is it. Each pot measures 0.5 high by 2.5, & once you add 3/4 cup of water (per disc) it will expand to perfectly fill one of our biodegradable coco coir pots. We sell these items individually, i.e. 1 unit = 1 soil disc. Expanding Soil Disc, Seed Starting Potting Mix, Disc Contains Worm Castings & Water-Retaining Crystals, Mix