Right, now the fields are clear and some early money is coming in, let's get some crops growing and making proper cash.

Till the fields with the hoe, and then use seeds - either the mixed ones you can find, or the ones you can buy at Pierre's - on the tilled ground to plant them. Then, simply, water them with the watering can.

You'll need to water them all every single day - um, unless it's raining - and eventually you'll have fresh crops for you to fill the shipping bin with and rake in the cash.