There isn't currently a way to restart your game yourself. We're investigating this as an option for the future, but this isn't something available in the game at the moment.
With that said, if you've hit a roadblock and feel that there's some reason it'd be easier to start over, we're happy to do whatever we can to help you.
Remember, though: there is no losing in Grass Roots! There are always ways to earn more Coins and Potbucks, complete jobs on your job board, and harvest plants.
We can reset your farm back to Level 1 if you submit a ticket, but keep in mind you'll lose all of your progress, including any Slackers, Gizmos, or achievements you've earned! If you'd still like to reset your game, please try using Floydbot. To do that, go to https://grassroots.zendesk.com/hc/en-us and click or tap on the image of Floyd at the bottom right of the page.