This is where the fairies learns how to prepare potions in their Potionology class.
In "The Secret Greenhouse," with the Winx, Flora is still perplexed by Eldora's flower, and Bloom suggests taking it to Palladium after his Potionology class. The pixies decide to break into his lab to see what is going on.
During the class, Palladium begins his lecture on Potionology and uses his lesson to restore the three freshmen students who had been turned into frogs by the Trix. He gets annoyed when he sees the pixies accidentally make a mess on the table next to him and shoos them off. He resumes his lecture on how to make metamorphosis antidotes, which Roxy takes an interest in.
He then tells Roxy to work her animal magic to amplify the potion he mixed to use on Griffin in the form of a crow, who then reverts back to herself. Griffin was woozy and nearly collapsed, but is caught. She insists on seeing Faragonda quickly, but Palladium has his students take her to the infirmary to recover. Flora then quickly asks Palladium about Eldora's flower and if he could identify it. Unfortunately he could not, but he was surprised to hear the name Eldora.
He reveals a fairy of that name once lived at Alfea and taught floral magic in Alfea's Greenhouse. Flora was shocked to know there was a greenhouse on the campus unbeknownst to her, and Palladium said it was because it had been closed and abandoned ever since Eldora left, locked away in the vaults. An excited Flora runs to where it is followed by the others.
Later, Bloom and Selina enter the lab, then a plant monster breaks through the window. Bloom transforms to fight it and tells Selina to concoct an antidote for Flora. Selina smirks as all was going according to her plan. Selina spikes it with a lethal poison and proclaims to Bloom she made an antidote just in time before tossing it to her. She tells Bloom to hurry and get it to Flora while she takes care of the plant monster. Once Bloom leaves, Selina reverts the monster to its former state. The Trix observe the event from Cloud Tower and were impressed by Selina's subterfuge.