Hey All,
Just sharing some work I've been doing with my two arduinos. I got turned on to arduino about 9 months ago after seeing this youtube video: Arduino Greenhouse mrk 2 - YouTube
While my attempt at a garden is feeble compared so what he's got going on there, I've been learning a ton and am really enjoying it. Here's a few pictures.
My second arduino is dedicated to this small novelty greenhouse right now I have programmed temperature controls adjustable via TFT, moisture, humidity and temperature monitoring. I've got a Lipo shield in there w/ a large size battery -- I had plans on using solar, but w/ the TFT it's not that easy. My next plans are to add small LED grow lights based on this tutorial:
https://www.circuitsathome.com/diy-2/high-power-led-grow-light-a-build-log
greenhouse front
greenhouse control w/ simple menu functionality to toggle temp targets/fan override etc.
My first attempt was a windowsill planter box. This worked out really well and I've been using plot.ly to graph the results (haven't had too much luck w/ plot.ly, interface is buggy but they seem like they're always updating it. It's gotten better over time). I am using a water pump and a growler for the water reservoir. I had an aphid infestation that's killing the plants, plus my cat chewed some wires, so it's currently out of commission.
I think i'm going to repurpose the mega for the small greenhouse as I'm running out of pins quickly.
Thanks for looking! 
planter box
whole view
planter control