My setup to the image above with a few exceptions:
Currently it looks like the furthest wires I'll need are 40ft(20ft x2) just for the solenoid and I'll need slightly less for each solenoid closer to the breadboard. I'm also looking to add some capacitive moisture sensors which will add more than double the amount of wiring required. For just 6 solenoid valves and moisture sensors the wiring doesn't seem too daunting but I am hoping to expand up to 24 valves and sensors within the coming months and I can't imagine how much wiring will be necessary to accomplish that.
The use of the setup is automate the watering process of my vanilla orchids. I have 6 now but pretty soon I will be able to cut their pieces of them and grow new orchids from them to fill my garden.
The best solution I can think of is positioning the system in the middle to reduce distance from the controller to the nodes. I was hoping there were some possible solutions I am not privy to as I am more programming oriented than engineering and had only every taken a single circuits course.