hwo. garden allows you to grow plants, these plants cause you to increase a bar up to 50% which changes what animals appear in which game.
carrot spawns pig which has a base value of 5.
turnip spawns cows which have a base value of 25. I don't know what the cracked spawns but my guess its base value is 100. and the ? will spawn something that gives 500.
this will upgrade what you make in each game. in mowing, as far as I know the animals are just a tiny money boost. however in breakout, a 5x muliplier on a 25 dollar cow is way more then a 1 dollar goat. however to get the more valuable animals you have o be active in growing then picking the crops to keep the % high, as the % lowers over time.