Asparagus is an easy to grow and hardy herbaceous perennial. Although dormant in the winter, its delicious edible spears show themselves in early spring. Asparagus needs a deep, organic and well-drained site in full sun. A permanent place in your garden is preferred, as the plants can produce for 10 to 15 years.
When starting, be sure to prepare your site well. First off, locate a well-drained, sunny spot with rich, loose soil to place your asparagus patch. If your soil tends to be hard or shallow, consider working in a hefty amount of compost or planting in a raised bed.
Dig a trench about 10” deep and 12” wide. Lay about 4 inches of compost in the bottom of the trench, bringing the depth of the trench to about 6 inches deep. Apply 2 cups of Down To Earth All Purpose 4-6-2 Fertilizer and 2 cups of agricultural lime per 10 feet. Mix the fertilizer into the underlying compost.
Place crowns in the trench, and arrange them so their centers are 12” to 18” apart. Cover the crowns with 2 to 3 inches of garden soil that has been mixed with equal parts with compost. As shoots emerge, add more of this mixture until the trench is filled to where it is level with or slightly above the surrounding soil. Sprinkle the area with a slug bait like to prevent slugs from damaging young shoots.
Fertilize asparagus twice a year. In the spring when spears first start to emerge, apply 2 cups of Down To Earth All Purpose 4-6-2 Fertilizer per 10 row feet, then cover with 2 inches of compost. Repeat this application in June immediately after the final harvest. Every second spring, apply 2 cups of agricultural lime per 10 row feet along with the spring fertilization.
For your first year, do not harvest your asparagus. In the second year, harvest several times over a three week period. In the third year, harvest over a four week period. Thereafter, you can extend the harvest period for up to 8 weeks.
Harvest spears with tight tips that are between 7 inches and 9 inches tall. Snap them with your hands near or just below the soil surface. You may also use a sharp knife but take care not to damage other emerging spurs.
After harvest, allow the spears to fern and grow until they are killed by frost in the fall. Then, remove and compost them. If ferns are left on the bed, they make prime habitat for asparagus beetles.