What are the names of the herbs that you are trying to germinate ?

50F is definitely too low in general to germinate most seeds. And, to germinate, light is not needed. They will need light after germination.

You are better off germinating in the house. Most people do it on the top/back side of refrigerator. KEEP them in dark until they germinate.

Another point:
IF you are in USA, zone 8 or lower, I think it is too early to start herb seeds at this time of year, if you are going to plant them out.

Those of us who grow lots of things from seed will provide bottom heat for the germination process in the form of heat mats or heating cables, if you use a germination flat. The bottom heat is turned off after germination is successful. The temperature of the garage doesn't matter too much. Most people do not use the top of the 'fridge. I don't think so, anyway! :-)

Whether your seeds need light or dark in order to germinate depends upon the kind of plant. I've had one germination flat with some of the seeds covered and some not many times.

You can grow some herbs under lights for an extended period of time, as long as the potting medium is porous and fast draining. 50ðF will be tough going for some of the Mediterranean type herbs.

These are not seeds to germinate. They are actual plants that I ordered --oregano; dill; marjarom, basil. I already have a big pot of rosemary and a small lemon thyme.and chives. Thanks for the help. Barb

The thing about overwintering perennial herbs is that most still need a dormancy type period to take a break--it's hard on them to force growth period year round. I keep rosemary, oregano, thyme, lemon thyme, garlic chives, marjoram, bloody dock sorrel, bay, and scented geraniums inside with lights over winter. With the exception of the chives, I don't plan on large harvesting from them throughout the winter--if you're just talking a sprig or two occasionally then you'll be fine, but you won't be able to make a big batch of pesto or large quantity harvest.

I think you're going to have a very hard time with the basil--50 is way too cold and about the minimum temp that basil will barely grow at. I've never done dill potted, so can't advise on that one, but it's a shorter lived annual so you're not going to have it all winter. The others will probably live and be fine, but not grow overmuch. I do recommend that you make sure you're setting the lights to a shorter time than you would in summer growth period. You'll be able to get some harvest, but don't expect the explosive growth that you can see on some in summer.

Oh, and watch your watering--at that temp they're not going to drink much. Make sure they're not waterlogging--rosemary, oregano, and thyme are very prone to root rot potted.

Thanks for the help. Balloonflower, I don't have a timer on my lights. I just supposed they would soak up what they need. This may not work. I may bring the basil into my sewing room where there is a lot of natural light. Just wanted to have herbs other than the dried. I don't like to buy those packages that they have of fresh herbs. Am trying to root some of the Tai basil which has such a delicious smell, but not having much luck. I have some in water and some in a little pot. The kind I bougt is called Sweet Basil, I believe. Barb

Heated garage? Or just a heater for the plants? My unheated garage does get to freezing temperatures in the winter. If it is just a heater for the plants I don't expect that to work well come the bitter January cold.

I only use the garage and our unheated porch for keeping plants that are dormant and that can take freezing temperatures but not the full brunt of the winter cold here. In the house under lights would be better, imho.

FataMorgana

Fatamorgana: My garage is heated. My son has set the thermostat at no lower than 50 because my washer and dryer are out there. I know the rosemary is happier out there because I had some out there last winter. I tried keeping it in the house and it was not nearly as happy. I will find out about the others. I don't think the basil will like it. Thanks for the help. Barb