Asparagus grows best in deep, well-drained sandy loam soil. Perennial weed problems must be removed at least one year in advance and soil pH needs to be brought up to near 7.0. Phosphorus and potassium levels should be increased before planting if needed. Each year after harvest, 50-100 pounds of actual nitrogen should be broadcast.
A middle buster which throws soil in both directions, should make a trench approximately 8” deep, in rows 4’ or 5’ apart. Most growers use row spacing that fits their equipment. The asparagus crowns are then laid in the trench 8”-12” apart. This will require approximately 8,000 to 10,000 crowns per acre.
Cover the crowns with 2”-3” of soil. Once the asparagus begins to crack the soil (but before it emerges), gradually fill and cover small weeds. Eventually, the furrow should be level with surrounding soil. Control weeds and insect pests, and water when necessary. Fern can be left standing all winter where it catches snow and provides an attractive cover for wildlife.
Mow the fern down the following spring, then apply a pre-emergence herbicide over the shredded fern. This should all be done 2-3 weeks before spears emerge.
Vigorous stands may be lightly harvested the second year, but on a very limited basis. Each year, the harvest can be extended until full production is reached in 4-6 years. Stop the harvest when ¾ of spears’ diameters are less than ⅜”. An asparagus field can last and be productive for 10-20 years.