Asparagus-grow sacks?

I have lived in rented houses the last few years so I have kept my plants such as Blueberry/cranberry bushes in containers and I have a couple of dwarf apples also in big containers, I grow a fair bit of veg but I am still finding my feet with it and this garden......In some of the lovely garden brochures I have been sent are details of a new product as well as Potato grow sacks they are now selling Asparagus ones.......Now I know enough about Asparagus to know it has to be left for 2 seasons before you cut spears but this catalogue makes no mention of this fact Not sure if its because they have some new variety or cos they are trying to sell loads....can you grow Asparagus like this in a potato type grow sack? I know that at least one of the reasons you dont cut spears initially is because the plant needs to put on growth so it can recover when you do start to harvest, if you cut a crop initially then would it make this Asparagus a disposable annual really?