Temperature, Soil, and Fertility
Asparagus is most productive in deep, well-drained, sandy loam soils, but will do well in other soils, providing there is proper drainage. The soil reaction (pH) should be maintained between 6.8 and 7.0. Medium fertility is best because it produces a balance between top growth and root growth.
Asparagus should be planted with other perennial crops on the north or east side of the garden so it will not shade other vegetables or low growing fruits. Plant in spring, about the same time as potatoes (typically around mid/late March here is planting zone 6). Before planting, broadcast and turn under 1.2 lbs. of 5-10-10 fertilizer (or equivalent) per 100 square feet of growing area. If pH is below 6.0, lime should be included with the fertilizer. Lay crowns on their side at the bottom of a 6 to 8 inch deep V-shaped furrow and cover with 1 to 3 inches of soil. Spacing for crowns is 10 to 12 inches apart within the row. Each row should be between 4 to 5 feet apart. If only one row of asparagus is planted, allow at least 3 feet between the asparagus and the closest other vegetable crop. As the asparagus grows, gradually fill in the furrow with soil so as to avoid covering any asparagus foliage. The furrows should be filled to ground level by the end of the first growing season. Side dress with 1.2 lbs. of 5-10-10 fertilizer (or equivalent) per 20 feet of row in late July or August. Adequate soil moisture is important during the first growing season. Weekly applications of irrigation to wet the soil 8” deep should be sufficient. Late in the fall of the first growing season, after the brush has turned completely brown, remove the brush (old stalks) and any weeds. Early next spring, maintain the proper soil pH plus follow the 1st season’s fertilizing schedule. Remove the brush each succeeding fall after it has turned brown. Before the asparagus emerges, broadcast lime, if needed, and spread 3.5 lbs. of 5-10-10 fertilizer per 100 square feet of bed. Maintain good foliage growth and keep your bed free from weeds.
Harvest for 2 weeks in the second growing season as long as the foliage growth was 4 ft. or more in the previous year. In the remaining growing seasons, harvest for the full 6 to 8 weeks. During the harvest period, harvest all spears that emerge.
Storage of Crowns
If storage is necessary, store the crowns in a cool, dry location until planting is favorable. Should the crowns dry, soak them in water for one hour before planting.