Probably not. Most windows block most if not all uv rays. They let through a lot of light but the light you need is filtered out for energy efficency.

Damn energy star windows...
Slevinkal Reviewed by Slevinkal on . them bloody noobs :rasta: hi,just wonderin is it essential to have lights on ur plants to make them potent? i just have natural light & ventilation as its on a windowsill. thanks X :wtf: Rating: 5