My basil has produced very nice white flowers. It's still cold outside so I can't put the plant out and let nature take its course. How do I successfully obtain seeds from the flowering plant? Do I have to cross pollinate, or does basil take self-pollination? After how long will be plant finally die after the process took its course? I'm doing some experiments here, so please bear with me.
Basil will self pollinate, but I guess you might need to manually spread the pollen around yourself, given the lack of insects indoors (I'm not sure). Every single flower on my perennial basil seemed to be successfully pollinated this year without effort on my part, but I have had bees helping out mightily.
After the flowers wilt and the stems carrying those flowers begin to brown you'll find that the flowers have turned into little brown containers carrying 4-6 tiny black seeds per floret. Although the leaves are still green it doesn't look especially attractive at this point so you might not want it cramming up your favourite windowsill view.
Each seed is slightly oval-shaped and probably less than 1mm in its broadest dimension. Wikipedia has a picture of the seeds.