Asparagus is a perennial vegetable that can thrive in the home garden for 15 years or more when well cared for. Asparagus plants should grow for 1 full year in the garden before they are harvested. Asparagus is most productive on deep, well-drained, sandy loam soil, but it will do well on other soils if it has good drainage.
Asparagus should be planted with other perennial crops in the early spring. Before planting, add compost and organic fertilizer to amend the soil. If pH is below 6.0, lime should be added to correct Ph. Dig a V-shaped furrow, 6 inches deep. Plant crowns with the buds up in the bottom of the furrow, and cover them with 1 – 3 inches of soil. Space the crowns 12 to 16 inches apart within the row. Allow at least 3 feet between the asparagus rows or the next closest vegetable crop.
THE FIRST GROWING SEASON
As the asparagus begins to grow, gradually fill in the furrow with soil. (Be careful not to cover any of the asparagus foliage.) The furrows should be filled to ground level by the end of the first growing season. Add organic fertilizer (about 1/4 cup per plant of granular) spreading the fertilizer on each side of the asparagus and cultivate it lightly into the soil. Good soil moisture is important during the first growing season. Irrigate or water your asparagus enough to wet the soil 8 inches deep every week. DO NOT harvest the asparagus spears that grow during this first season ! Allow all of them to grow into brush. Late in the fall of the first growing season, after the brush has turned completely brown, remove the brush (old stalks) and any weeds.
THE SECOND GROWING SEASON
Early next spring, broadcast lime as needed to maintain the proper soil pH. Add compost and organic fertilizer again. Thorough watering (2 to 3 inches of water) slowly applied every two weeks during dry weather is sufficient. Remove the brush each succeeding fall after it has turned brown. Each succeeding spring, before the asparagus emerges, broadcast lime if needed and add compost and organic fertilizer. Rake the fertilizer and lime into the soil gently, 1 to 2 inches deep. Take care not to damage the asparagus crowns.
Use a knife to harvest spears. Use one hand to hold the top of the spear you are harvesting. Cut the spear off about one inch below the soil line. Be careful not to cut too deep – it will damage the asparagus crown. Harvest all the spears that come up during the harvest season. A good general rule for length of harvest season is the 2-4-6 week sequence. Harvest for 2 weeks the second year the plants are in the garden, 4 weeks the third year, and 6 weeks the fourth and all following years. Each succeeding fall, remove any brush after it has turned brown. If you harvest asparagus that will be consumed later,wash the spears and place the cut ends in about 2 inches of water. Like fresh flowers, they will keep in the refrigerator for several days.