Scrape the bark off in a spot and see if the wood looks green, if so it is alive. I have had the best luck by cutting off a young green branch either in fall or early spring and planting it directly into the ground where I want the willow to grow. Dig a hole with post hole diggers and plant about 2 feet of a 3 foot long branch into the ground with the tip of the branch pointing toward the sky. Backfill with amended dirt that will retain moisture. Then water it as needed. It will need a lot less water and care than in a pot and have a much better chance of living.

I just put them in a bucket of water and in 2-3 weeks they have roots and they're ready to go in the ground.

-Little John