should be have as the period is from Nov to Jan but best period is in Dec.
just book a tix for my to sunflower fields in early Jan 18. Will be going to Lop Buri and Saraburi. I will be renting a car.
I was told it will be best to go there early. So properly you need to leave BKK very early or you stay over at Khao Yai and go there nearer.