I believe that indicator has been there the whole time even from the launch. However, at that time the indicator was only smiley face to let you know how the plants are doing but after some patches, they include the flower thing to help us know when our plants are ready to evolve. For me, with Get to Work, I prefer raising quality from the produce using chemical analyzer but without access to Scientist career, you need to be at least level 5 in Gardening to do that.