dirtslinger:

1. Pollination is not an issue for raspberries, so the only consideration in spacing a planting of two different varieties is the possibility they would eventually grow together and get all mixed up. Raspberries do spread.

2. It's a little arbitrary to say just how wide a raised bed should be, since it is really a question of your own choice and convenience. But I would say 3 feet would be about the minimum, and 4 feet would be better, if you have access to both sides of the beds. Most raspberry varieties (you don't say what you are planting) will spread and fill in the available space and more, so after a few years it won't make much difference whether you have planted a single or double row. At that point, your task will be to keep them thinned out a little and confined to their bed.

Don Yellman, Great Falls, VA