For the light element i chose a very simple circuit, some power leds 1 watt, with a resistor drop supplied by a 5v from a mini usb connector. i have added a diode or fuse as an optional voltage drop / short protection. Its not an efficient circuit but very simple to assemble. and very cheap :).

The components were sourced from various suppliers on ebay. and the circuit was ordered from SeeedStudio. Since they have started free colour add-on for the pcb i wanted to test the various colours you can get, so here is the yellow option :).

I added a simple bracket designed in Fusion360, to mount the LEDs on the shelves where i keep the plants: 

As a side project i have made a custom table lamp, (this time using regular 1 watt , white leds )

Assembling the pcb`s is quite simple by hand, but since i have discovered the comfiness of stencils there is no going back. So i have ordered a stencil from OSHStencils, and assembled all 9 circuits in one go using my re-flow oven.

I have tested re-flowing the circuits with the leds, but it turned out not so good an idea, (they have melted a bit, so i soldered them post process).

Now my plants are happy :)