Be patient. A couple of crowns I moved last year are just coming to life, though the established plants are well on their way.

Have you mulched the surface with something biodegradable? I think that will be much more useful than taking any other step. The roots will move up or down to find their most comfortable depth over a period of years, and it all works best with good top-down fertility that creates habitat for night crawlers and suppresses weeds.

Asparagus is a great plant for a slope. Stop worrying, the drainage will take care of itself.

Can anyone tell the difference in the different Jersey varieties?
4 years ago I planted 10 crowns of Jersey Knight, Jersey Supreme and Jersey Giant.
I cannot tell much of a difference, though I haven't kept track of how many spears I have harvested from each plant, just looking down the row it looks about the same. I am thinking with just a few plants it won't make much difference, maybe if you had acres it would show a difference in volume.
This year I wanted 20 more plants and the Garden Center I bought from only had Jersey Knight and Jersey Supreme so I bought 10 of each. I planted them March 20 and as of last night I can see 18 plants. I live in WI and it was 80 when I planted them but now we are much more normal with getting frosts almost every night.

Thanks Planatus- no mulch yet (trenches only part filled). What works well for asparagus? Wood chips?

Thanks Buckyz4 - will be patient. Had read emergence in a week through 6 inches, but that must be an over-generalization and too short a time.

Did you fill in the trenches all the way at planting?

Right now I'm throwing grass clippings on my asparagus, but that supply will soon run short and I'll switch to a mixture of weathered sawdust and wood chips. My garden soil "eats" a lot of wood and has a good appetite for the stuff.

I planted 40 Jersey Knight crowns in clay soil last May; it was cold and wet until June. I read conflicting information about planting in clay soil, whether to amend it, what depth to dig the trenches. So I loosened the soil about a foot deep, forked the subsoil a little and replaced the original soil mixed with compost and a few natural amendments to within 6" from the top. Planted the crowns, covered them with a couple of inches of soil and compost. It took about a month for all the spears to come up. Of 40 planted, about 38 came up.

So far only about half have come up this spring, but I expect most if not all to emerge. They look pretty healthy.