Red Wigglers will not survive just out in a garden. You'd want earthworms for your raised bed.
As for the rumor that worms are "killing" trees, they are not killing trees. They are composting the decaying material on the forest floor faster than in the past when there were no worms in the habitat of the forests. This is changing how the forest lives. Worms are not native to the areas being talked about.
Bentley over at redwormcomposting.com has some posts from a week or two back where he showed the results from digging trenches for his worms next to his vegetable garden. He got some great growth that way, but I think it took several pounds of worms to get the system moving.