Infernal Dragon Soul not working on Zyra plants

Yeah. Is this intentional? Seems like a bug. Why wouldn't you have made it so that the plants work with Infernal Dragon Soul? Zyra's kit is mainly dealing damage with her plants. Her passive literally sets up damage to be dealt by the plants... Her Q is literally only a plant spawner. Literally no point/not satisfying to have Infernal Dragon Soul while playing Zyra.