The Boseong Tea Plantation Light Festival (보성차밭 빛의 축제) will run from December 11th, 2009 through January 31st, 2010. Here's a picture from the fields in December, 2005:
And another look at the fields covered in snow:
You'll find plenty more pictures here, though the ones from the 2010 festival are of course done on a computer. The fields will be lit up from 5:30 pm to midnight each day. According to the Gwangju bus terminal site, buses run frequently to Boseong:
6:10 6:40 7:15 7:50 8:30 9:00 9:30 10:00 10:30 11:00 11:30 12:00 12:30 13:00 13:30 14:00 14:30 15:00 15:30 16:00 16:30 17:00 17:50 18:40 19:15 20:00 20:40 21:40
If you live in Suncheon, you can use the same website but select 순천 from the drop-down menu. Buses run to nearby Boseong county pretty often. There are then buses from the Boseong-eup terminal, and from Boseong Station, to the tea fields, though the Boseong county website doesn't provide a timetable.
I saw Korea.net put something up on this a couple days ago---before I published this, but after I post-dated it---so let's see what wonderful news they bring:
Boseong, the green tea capital, will present the nation's largest green tea field tree, which will strike a beautiful image of Boseong into the hearts of all its winter guests. Those who visit the festival will wish to stay longer in Boseong and participate in all the events, rather than merely passing through.
I'll reuse last year's post and write that should the image of a tree strike your heart in some way, and should you want to spend the night and see the tea fields again in the day, there are a few motels in town, as well as a ton of more expensive pensions.