Days to Harvest: 2 to 3 years after initial planting. Perennial, harvest early spring through early June.
Temperature: Cold season, 60° to 65° F is ideal.
Companions: Dill, coriander, tomatoes, parsley, basil, comfrey and marigolds.
Avoid Planting Near: Onion, garlic and potatoes.
Preparation: Asparagus is a perennial vegetable that lives 12 to 15 years or longer. Prepare bed for initial planting as early as possible. Double-dig bed and enrich with compost. Then, dig 12-inch deep trenches, 12 to 18 inches wide, with 4 to 5 feet between trenches.
Planting: Plant one year crowns in early spring. Set plants 15 to 18 inches apart, mounding soil slightly under each plant so crown is slightly above roots. Spread roots over mound and cover crown with 2 to 3 inches soil. As plants grow, continue to put soil over crowns (about 2 inches every 2 weeks) until trench is filled.
Spacing: 18 inches between plants, 3 feet between rows.
Water: A flush of spears often follows a soaking rain.
Harvest: Spears should not be harvested the first season after crowns set. Harvest lightly for 3 to 4 weeks the second year. In the fourth season, harvest 8 to 10 weeks a year. Harvest spears just under soil surface when 6 to 8 inches tall and before tips separate.
Tips: Asparagus does well where winters are cool and the soil occasionally freezes a few inches deep.