Plant hormones are like tiny messengers inside a plant that tell certain parts or cells what to do. They are made of special chemicals and help the plant stay healthy and grow in the right way. When the hormones travel around inside the plant, they act like signals and tell the plant how to do things like make new leaves, flowers, fruits, and help it use water and the sunlight it needs to grow. Without them, plants wouldn't be able to do all the things they need to do to stay healthy and survive.