Orders for your crops will be coming and over time they will be coming faster. You start with one type of crops and slowly expand your crops arsenal. Each new crop you add takes a bit longer to grow, but will make you more money, So it will be worthwhile.
To plant your crops, just drag them from the bottom row and when the timer is done, just drag your crops to the right order.
In addition, there are some special items that will help you manage your farm.