So here we go, an edited updated version of how Root of All Evil may probably been better.
The storyline of visiting the park's greenhouses and something goes horribly wrong is good, but lets make it better. How about they give a specific story about the Lady of the Gardens and explain how she came to be. Like a background story for whole Dark Side of the Gardens theme. For example, a little girl gets lost in the park's greenhouse after wandering off away from her parents into an employees only area, and then bad things happen like a zombie mutation, and after all these years she is claiming the park to be hers. Gives it a little depth into the background of the Lady and the theme of the event.
If this maze is about going through the park's greenhouses in an employee only area, then they should do just that. I think they should have the entrance to the line say Team Members Only Please, Thank You, and then have the sign taken of by vines with the eyeball rose. It's an employee area, why not leave it so? I understand not showing guest all the behind the scenes stuff, but there is no need to cover up a whole bunch of things that guests should expect to see in an employee area. Not saying the park should just let guests walk into an employee area without limitations to what they see, but don't try to cover up everything, especially putting random plants along there. Plus rock speakers in an employee area? Come on, the illusion is broken already, use the real speakers, the ones that guest can see as well throughout the park, that look like real speakers.
I think the layout of the house needs to focus more specifically on the greenhouse idea. Build the mini green houses to be long, like actual greenhouses, scaled down a bit, and then in between these greenhouses have plants in actual pots not those ugly boxes, and have plants that would usually be in the park's green house. Huge trees can make walls, but really, if the greenhouses are going to be your rooms, you should only need small pathways between them and they could use hanging plants from like a wire to be used as a wall. Make it more of a real green house feel. Have the scare actors dress in the actual Landscaping Team Member Costumes. If they want to split groups up with separate paths, do it inside a greenhouse. Each greenhouse can have multiple things on on inside not just one main theme, Poison room, etc. Try to have many things going on in one place.
If you are going to sell pictures of going through a maze, have the camera hidden inside the house and not pre-plan it just outside the front door. A photo of a truly unexpected scare and picture is ten times better.