I'm not sure it makes much difference :-) We grow an awful lot of bulbs here in the Skagit Valley....more than just about anywhere outside of Holland. And they grow in heavy soils that have to be bermed or dyked to keep from annual flooding, much as they do in the Netherlands. It is certainly not light fluffy soils - you sink down several inches just walking between the rows. But the tulips grow and flower on long stems and in fact are harvested for the cut flower trade. The bulbs themselves are later harvested for sales and for export.