When are the rice terraces in northern Laos typically harvested? When we were in Vietnam last year the rice had already been harvested- the terraces were still stunning but when we return to the region we'd love to see the terraces with rice and want to time the trip accordingly, although looking at next fall.
The harvest in northern Laos is typically around now.
Best time to see the vibrant greens is around July-Sept during the peak-end of the main wet season.
Rice in Laos isn't typically terraced like the famous areas in northern Vietnam (Sapa etc) or Banaue in the Philippines though. There are some smaller terraces through descending valley bottoms, but not down the side of mountains on a large scale. Most Lao rice is grown on flatter flood plains.

Think northern Laos was around Nov, saw some harvesting last time I was there, in December there was still some being harvested. If you want to see the green rice shoots then you need to go in the wet season around around June/July time. Agree not really terraces in Laos, not like China, Vietnam and Philippines. In China the flooded terraces after harvest look stunning, thats around Nov - February.