If you've never played it, indie darling Minecraft takes place in a world made of blocks. So if you were going to build your own little Minecraft world, well, you'd need some blocks, wouldn't you!
Etsy user Laketide is selling these replica dirt-and-grass cubes to help get your collection (or horribly expensive world-building) started. Available in either 1.5" or 2.5" size blocks, they're actually made of wood, and are hand-carved and painted to look more earthy.
The downside is you can't actually grow grass like that. The upside? They'll never die, won't smell, and will slot together quite nicely without ever needing to be watered!
The smaller blocks are $8 each while the larger ones are $10 each. Or, for something a little more intimate, for $15 you can get a 3" block with a flip-top lid.