The snow just begins to melt in March, and there is still ice on the road. You'd better wear warm thick clothes like wool sweater and down coat. You can take a direct bus from Chengdu xinnanmen bus station to Jiuzhaigou directly. For accommodation, you may just stay at Sheraton Jiuzhaigou Resort or New Jiuzhai Hotel, Jiuzhaigou.

Thanks for the quick reply. I would also like to know what conditions are expected in mid-march in the Songpan area (will horse treks be possible?) and Huanglong valley. I read that Huanglong might be closed until 1st of April. Any other remarks about the area at that period are more than welcome. Thank you.