Hello I'm a new DM...kinda, I need a little help on some Ideas for some Dungeon room idea's. i've created a dungeon using the magnificent mansion spell as a base and I'm almost ready for my low power setting(Lvl 3 to be specific)victorian one-shot. but im spacing on the last two room's. the whole idea of this dungeon was inspired by escape rooms and the deadly movie versions. now the rooms that i need to outfit are the green house, and the study. But im having a hard time with nature based escape room & a non-gentic escape room for the study. please help me out if you can any thoughts would be of help.

Well, there's a ton of plants in D&D lore, perhaps the players need to solve an alchemical puzzle to treat some overgrown razorvine before it consumes the room? Get the chemicals mixed wrong, the plants grow/attack/contrict/become sentient/etc. Or perhaps a flower is producing a poisonous gas and the party has to mix an antidote using ingredients in the greenhouse while holding their breaths. 

I'm not sure what you mean by "non-gentic" unless it was a typo for non-generic? But here's something I did recently that might give you ideas:

I threw a mirror room trap at my players last week. Room had an arcane security spell (basically, Demiplane) that went haywire and trapped someone inside. Party had to figure out the faulty rune and fix it from the inside to rescue the trapped person. Catch was, the room was a mirror plane, so all magic was reversed. (Detect Magic became Detect Mundane, Cure Wounds became Inflict Wounds, Dispel Magic became a wild magic surge, etc.) They found three runes behind three giant mirrors and realized the north and south mirrors were hung on the wrong walls, and the divination anchor rune wasn't fully powered. They freed themselves by pumping non-divination magic into the divination rune and re-hanging the mirrors in the correct spots. They also fooled around with the Opposite Day magic and had a blast. You could always add air scarcity or flooding or shrinking ceiling to make it more of a time-sensitive escape.

For the Greenhouse, I would suggest some sort of plant/mushroom which shrinks the party. The party has to get to a medicine cupboard on the wall to de-shrink themselves using a marvelous elixir.

Not really sure how to make a Study work. Being Victorian era, perhaps the walls are covered in photographs, and one of the walls seems to actually be a glass window. When the players look through the window, they find themselves looking down on the empty study, as if from the wall. The door is locked behind them, and everything is sepia-toned, as if in an old photograph. There is a lock on the wooden frame of the window-wall, and they need to find a key to free themselves from the photograph! Classic escape room style, where the key's in a locked drawer in the desk, the key for which is hidden in... etc.

When they unlock the frame, the room pitches them out into the study itself, and they find the walls are covered in images of skeletons in the study, from the people who never made it out.

Alternatively, have them start to experience petrification, contested against constitution, as they start to freeze into the image. The images around the study may feature people in various stages of solving the puzzle, giving up, attacking the (indestructable) glass, and so on. If they need hints on solving the puzzle, they can look around the study and see people partway through the solutions.

Thanks for the reply and for the Green room idea. And yes gentic was a typo....egg on face and all that. As for the other room...the reverse magic effect has given me idea's, so I say again thank you for your thoughts on this.