I'm not sure how much actual help Regulus will be with the flowers since I reckon he never liked Herbology much - getting dirt all over his pureblood hands ewww! - but he shall try his best. And simply hope for the best in regards to Tabit and Trenna. This can either go splendidly or they end up giving another ideas...

Behave around the potions, Zack, the new potions lab is in the basement of wizardhouse so...

...

Actually, Zack, please do play around with the potions. It would solve all his problems!