no protection required, the underground parts are as hardy as a hardy thing.
To Amanda21; Personally, I prefer a single row as they have less competition on 2 sides, in blocks, they have more neighbours. However its all down to choice really, if blocks are more convenient, then so be it, as long as they are a good distance from each other they'll be fine.
Remember, there's no art to growing asp afterall they grow wild in the most unhospitable places, i know of a good specimen on a railway enbankment, and another on a rocky cutting next to the M25!
To caroline7758, you dont say what variety, but I would leave to grow this year unless you have really strong growth, and wait for some fat spears in 2007. Yum Yum.
I like asparagus ;D can you tell?