Asparagus is a perennial crop and a planting can be productive for 20 years. Plant in full sun and a well drained soil with a pH of 6.0 to 7.0. The planting is established from dormant, one year old crowns, planted in spring. Seed may be used but it takes longer. Planting may be done as soon as the ground is workable. Do not buy moldy, wilted, or small crowns. Dig a trench one foot wide and one foot deep. Pile the excavated soil next to the trench and work in organic matter and 5 cups of 5-10-10 per 50 feet of row. Put 2 inches of this soil back into the trench then place crowns in the trench at 12 to 18 inch spacings. Spread out the roots then cover the crowns with 2 inches of soil and water. As the shoots grow keep filling the trench but don't cover the shoot tips. By summer the trench should be filled in. Rows are spaced 3 to 5 feet apart. Asparagus is fertilized twice a year with 3 cups of commercial fertilizer per 50 feet of row. Apply before growth starts and again when harvest is completed. Old ferns may be left until spring. Small weeds can be killed by spraying with a solution of 2 pounds of salt in one gallon of water. The salt will not kill persistent weeds and too much salt is not good for the soil or the asparagus.
Harvest should be delayed until the second growing season and then harvest only for 5 weeks. Starting the third year, a full 10 week harvest may be taken. Stop harvesting in early July. Spears are ready for harvesting when 6 to 8 inches tall and can be snapped or cut off at the soil line. If cut off below soil level, emerging spears may be injured. In warm weather, harvesting may be needed more than once per day. Use the spears as soon as possible after harvest.