I read somewhere decades ago that Cool White spectrum is good enough for seed starting, that you do not need the
additional red spectrum in the warm white, daylight bulbs,
and grow bulbs until plants start to flower.
This article on lighting for seed starting at Dave's Garden
(
http://davesgarden.com/guides/articles/view/464/ )
says:
Quote:
|
Seedlings don’t need full spectrum lights; the cool fluorescent tubes in a cheap shop light are fine.
|
Edit:
Cool white and warm white bulbs usually cost the same, so I tend to
put one of each in a 2-bulb, 4' fixture. When the bulbs have a few
thousand hours on them and I change them out for new ones, I may
prefer the warm white bulbs in some fixture where I reuse the old ones.
"Daylight" or "full spectrum" bulbs may be better if they cost no more
and last just as long, but the spectrum on any 4' flourescent bulb that
you find at a big box store is good enough for seedlings.