Rovers:
@Dustin, I do want to do the project and learn more about Arduino. Plus I really enjoy these diy projects.@Saildude, I tried to look up grow light but they are all either too expensive or not suitable for the space I want to put them. This said they all seem to follow the same configuration of LED (80%red 15%blue 5%white) so I am thinking of buying some single LED and try to replicate this mix.
You only think the LEDs are expensive. Compare to grow lights.
I have a customer doing the same commercially and they pay to have custom LEDs giving the wavelengths required for maximum plant growth. No idea what they cost.
Paul