Ginda,
When I plant asparagus, I dig holes that are as deep as the shovel,
about 12". Then I form a little mound in the center that is about 3" high.
The 'book' says that we should dig the holes as wide as the roots are so the
roots aren't crowded but I'm usually too much in a hurry for that (lazy?),
hence the reason for the mound. I position the crown on top the mound, give
it a twist and, voila, none of the roots are crowded. Then I sprinkle a bit
of dirt mixed with bone meal and cover the hole. ALL of my spears are
huge(!), thick, big diameter.
I haven't seen it printed anywhere but I'm convinced that asparagus
spears become thick in direct proportion to their difficulty in pushing up
through the ground. Mine were planted in yellow blow-sand. If I had clay,
I might have made the holes, maybe, 8" deep.
Something I read about asparagus is that, if they are planted deeply,
their roots will creep toward the surface. I've been spreading about 6" of
mixed leaves and pine needles every year so they will stay deeply planted.
I pulled some fence posts yesterday and was very glad to have had a
fence-post-puller because the posts were a foot deeper than when I set them.
I had set the posts in sand a dozen years ago; their spades were still in
sand but I had to pull them through 12" of black dirt and intertwined roots.
A hint for the next time you have to pull posts or stakes: I drive them
down about an inch before I try pulling them. It is alot easier to break
their grip on the soil by driving them down than it is to break their grip
by pulling them up.
I transplanted my asparagus yesterday. (Thanks for the info, guys.)
I noticed that the one plant which was, for some reason, much deeper
than the others is also the one plant that reliably produces the
largest spears. Any connection, or just random?