Confident is easy as long as you have some of the dlc such as spa day. Use the suggest self esteem exercises interaction.
Or maybe the mischief skill and install false confidence. But pretty much if you wait a confident plant sim should appear. I actually had a real problem with flirty as all the plant sims were non-flirty and just got angry at my sim trying to flirt. My sim got super embarrassed and nearly died lol.
In my game I only saw three plant sims ever. They showed up as happy, sad, focused (most common), or uncomfortable, never playful, angry, flirty or confident. As only three sims showed up ever and never more then two a day it took a while to get all the beans as is given the long cool down timer. Had I not manipulated them I would not have completed the challenge in the two sim weeks of trying. I had to talk to Jasmine twice to get the first plant sim to show and regardless of my conversations no more then the same sims would show up. I even tried traveling. Your lucky only flirty gave you issues, I had to manipulate sims for over half of the beans as I haven't seen a flirty, confident, angry, or playful plant sim I didn't manipulate into said mood. It is kinda moot anyway as the sim family I am playing are a bunch of blood suckers immune to the fruit. At least I got a cool looking tree out of it.
Good to know that "instill false confidence" and " suggest self esteem exercises" trigger a confident moodlet in case I create a normal sim to become a plant sim. Minus Vamp powers I was at a loss. Thanks Nindigo, Candyd, and Playalot I learned something new from you. It is much appreciated. Reggikko good information on changing them back.
One thing of note plant sims can be turned into vamps. I got mad at one of the three plant sims in my game and turned her as punishment after I got my last been. That might have been a mistake given how rare they seem to be in my game world if I start a boring human just to turn it into a plant sim. Actually a plant sim ghost sounds fun. Anyone know if the is possible?