I worked 4 bags of cow manure and 4 bags of leaves into a 10 X 15 area. I dug 3 rows about 5 feet apart, and about 1 foot deep. I poured Bone Meal and cow manure into the bottom of the rows, and spaced the crowns about 18" apart.
I planted 2 year old Jersey Knight crowns. This the 4th year so I should get some good Asparagus this year. Last year it was so warm, that the spears came up in February and I wasn't ready for them. Everything I read says to wait until about March or April before you pick, and them pick for 6 to 8 weeks.
When you get finished picking lt let the rest grow and make ferns, and add fertilizer. Next spring
mow it all down add some more fertilizer before they start to grow. Asparagus is a heavy feeder.
I like to mulch the bed to keep all the weeds
I like to take the full spears, and grill them with some Olive Oil, Butter and Salt. Yumooo!!!!!!