It depends on the seeds. Some do actually need light for germination. Those that don't need light to germinate will only have to battle algae if you keep them under lights before they sprout.

Most of my seeds are under lights during the germination process. I think this helps eliminate the leggines of the seedlings because when they do germinate the light is there. I planted some Pansies and placed them in a dark & cool area and I checked twice a day.I checked them yesterday morning and they had emerged overnight.These seedlings were very leggy so I placed them under the lights immediately. Hopefully they will be okay. I know everyone has their ideas about seeds but it is important to experiment to find the best way for you.

Here's a list of seeds that need darkness to germinate:

* Bachelor's Buttons
* Borage
* Butterfly Flower
* Chinese Primrose
* Coriander
* Forget-me-not
* Larkspur
* Nemesia
* Painted Tongue
* Periwinkle
* Phlox
* Poppy
* Pot Marigold
* Sweet Pea
* Treasure Flower
* Verbena

For all others, while light is not needed it certainly doesn't hurt anything to have them on (other than hurting the electric bill ;). Especially so if you can't check them frequently. Those of us who can monitor our germination trays frequently each day can wait till they sprout before turning on the lights or moving them to the lights.

For those that can't monitor so closely, note your days till germination on the seed pack and then turn the lights on a day or 2 before if you wish. If you still miss the "sprout" you can always deeply transplant that leggy seedling into a new container and then put it under the lights.

With experience, you'll note that you can see small "bumps" in the soil cover that foretells sprouting. ;)

Dave

Thanks for your responses. I think I am going to run a little experiment and see what I come up with. I do have one challenge to overcome and that is that my lights are in a cool room. This is fine for germinated plants, but the seeds I am starting like it warm.

Thanks again. I will report in a month or two.

Kay.

I start all of my seeds under shoplights, and place newly sown flats under the lights BEFORE germination. The lights warm up the soil and help the seeds to germinate. I turn the lights off at night for the dark period. It's worked for me for decades.

And at the link below is a list of plants that are reported by the UNM, (I think that is the University of New Mexico but I didn't check.), that do need light to germinate. The list says nothing about how much light or when the light is needed. It is posted on the extension service website.

Here is a link that might be useful: Seeds that need light to germinate.