Technically, all asparagus varieties can be blanched in order to produce white spears, but Voltaire was bred for the job. Voltaire asparagus seeds are widely used by European asparagus growers. White asparagus is more tender than green, with a delicate, mild, somewhat nutty flavour. Traditional growers mound soil or sand up around the spears as they grow in order to keep them white. It may be simpler to use some sort of wooden box or inverted trash can to keep the spears in the dark. If not blanched, Voltaire will produce tasty green spears. The whole point here is to prevent the spears from photosynthesizing and producing chlorophyll.