A simple daylight lightbulb. Buy mine at Bed Bath and Beyond. About 7 dollars each. I bought four, and that is all I need. All my seedlings were grown using these lights. I grow sarracenia all winter (seedlings) for 2 years under lights. The seedlings are usually 1 foot tall by the end of their first year. They mature in 3 to 5 years instead of the usual 5 to 7 years. VFT's can be grown under lights too, and will respond well to growlights.