You can get a paste-like flocking at a craft store like Joanne, and I think there's a spray, too. I've used the paste on the tips of the branches of small green trees to simulate snow and found that it doesn't go far but it's easy to apply and dries reasonably quickly. The paste I've used is gloppy. It wouldn't be possible to neatly coat each needle.

Thanks!
The only spray I've seen thus far was called "Santa Snow" and it has a much finer texture than the flocking on my tree (the way it came from the manufacturer).

I'll double check my craft store and see if there is something...thanks for the suggestion :)

Does the tree come apart in pieces? I wonder if you could just take the bare pieces to a tree seller or nursery that does flocking, and have them re-flock it?