anyone remember the name of a japanese shoujo manga where they have a priestess competitio...

anyone remember the name of a japanese shoujo manga where they have a priestess competition or something and they are competing to see who can grow the best plant? the plant is supposed to be a reflection of the person and somehow the female lead's plant is growing super well. there's an evil girl who also grows a big plant but then it turns into a monster and the female lead defeats the plant to save the evil girl.
also the male and female leads somehow knew each other but broke up? like the male lead is the female lead's ex maybe and it's really awkward when they cross paths. there's some scene of the female lead digging stuff up in the garden too i think.
please if you think you know this manga, can you tell me the title?