Lavender Dormancy Question

I've planted seeds of the types of lavender shown below and I've got a

question on their dormancy. I'm in

zone 4b so I will be growing them in pots in the future and bring them

inside.

I'm growing them under fluorescent lights at the moment and the seeds

were planted in July. Do they require

a winter dormancy even though they are young plants, and I have an old

fridge in the basement for this purpose.

1 pkt S3635 Lavender, French Seeds 3.75/pkt 3.75 1 pkt S3628-800 Lavender, Provence Blue Seeds 3.75/pkt 3.75 1 pkt S3634-500 Lavender, Spanish Eyes Seeds 5.00/pkt 5.00 1 pkt S3635-700 Lavender, Purple Ribbon Seeds 7.00/pkt 7.00 1 pkt S3636-100 Lavender, Fragrant Butterfly Seeds 5.00/pkt 5.00

We always give our lavenders a winter rest, since none of them are native in the tropics. We reduce watering and lower the temperature to around five Celsius degrees at night and 10-15 degrees during the day. On sunny days the sun will raise the temperature above that. We never reduce the light levels below what happens anyway in our latitude.
Your fridge might be too dark. An unheated south facing bedroom window would probably be better. If this is not an option try a short rest of about a month in the fridge at close to freezing ie about 5C or 40F.