The Michigan Asparagus Advisory Board calls asparagus "one of nature's most perfect foods." This healthful vegetable has no cholesterol or fat and is high in vitamins B6, A, C and thiamine. It's a long-lived vegetable but frost may damage young spears.
Asparagus requires a high pH soil of about 7.0. Asparagus crowns are planted 8 to 12 inches apart in a trench that is 6 to 10 inches deep and covered with 3 to 4 inches of soil. Rows are set from four to five feet apart. Organic compost and a small amount of phosphate fertilizer are then added. Plants are allowed to mature without harvesting for the first three years.
After harvesting, the spears grow into ferns with red berries; these ferns produce the nutrients for the crown to produce a good crop the next season. The ferns should never be pruned or cut back. They will die back with winter frost but the underground crown will survive cold weather and be recharged for spring production.
Frost Damage to Spears
Frost can kill young asparagus spears when they first emerge from the soil. They will shrivel and turn black, making them inedible. Cut off all damaged spears. An eight-inch layer of organic compost or other mulch will help to keep the soil warmer and protect the crown from very cold weather.