Frailty, thy name is asparagus

People who grew up around here talk about picking wild asparagus on the ditch banks in the springtime when they were kids. I assumed that meant that asparagus was relatively easy to grow, so I bought some rootstock several years ago.

When I bought it, the prevailing wisdom said not to cut it the first year, so I let it grow wild and free. By the second year, the prevailing wisdom said it's best to cut it, beginning the first year, so some of my asparagus must have gotten wind that I'd mistreated it and it refused to come up. In fact, every year, I have fewer and fewer stalks of asparagus coming up.

Oh well, perhaps it's because I forget to pick them when they're perfect and let them get stringy and woody, like the one that doesn't fit in the frame of this picture.
I don't remember what kind of asparagus I bought, but it's a pretty purple color, which makes it hard to see against the early spring dirt. It turns green when cooked.
Although the really tall one wasn't worth eating, the other two were tender and delicious. Not exactly enough to make a meal, however.

So what am I doing wrong? I've got no idea, so if you grow fabulous asparagus by the boatload, please enlighten me.