Open source developers have developed Farmbot , an automated solution for small scale/backyard farming where planting, seeding, weeding can all be managed like an app. Almost as if you were playing a video game. The actual robotic rig is designed to be inexpensive and relatively simple to build yourself with all components costed in specification. You can build your own but the developers are also putting together premade packages.
Another similar project Growbot can be found here also