Check this out, looking potentially cool: Horto domi: the Open Garden by Outer Babylon " Horto domi is an open hardware raised-bed garden unit with environmental control and monitoring via web-interface thanks to Arduino Ethernet. DIY sensors, such as those collecting moisture and temperature data help monitor the environment within the dome and will eventually be used to automate conditions. The goal is to grow whatever you want, whenever you want, wherever you are. " The link provides a video describing this thing in more detail. They're currently about $1000 from reaching their $10,000 goal of the kickstarter funding which ends May 9th. Cheers
The important thing is that the plans/blueprints/instructions etc. will all be open-sourced - thus modifiable... couldn't be difficult to simply raise the dome an extra 2 to 4 feet?