The perennial nature of asparagus offers the opportunity to plant a vegetable that will provide harvests for two decades or more from a single effort. Asparagus is typically planted using one-year-old bare-root crowns, which are the root systems of the plant with buds ready to sprout. Successful establishment depends entirely on careful planting and preparation. Planting the crowns correctly in the ideal environment guarantees years of tender, flavorful spears.
Preparing the Planting Site
Asparagus requires a permanent location since it is a long-lived crop that does not tolerate transplanting. A site that receives full sun for at least eight hours a day is necessary for the crowns to produce the energy reserves needed for subsequent seasons. The chosen location must have excellent drainage, as asparagus roots can grow deeply, but they will quickly rot if the soil remains waterlogged.
The ideal soil is a deep, fertile sandy loam, which warms up quickly in the spring and allows for easy root penetration. Asparagus prefers a slightly acidic to neutral pH range, typically between 6.5 and 7.0. A soil test should be conducted to determine if lime or other amendments are needed to adjust the pH. Heavy clay soils can be improved by incorporating large amounts of well-rotted organic matter, such as compost or aged manure, which improves structure and fertility.
Before planting, it is necessary to completely remove all perennial weeds, as they are difficult to control once the asparagus bed is established. Weeds like Bermudagrass or Johnsongrass compete directly with the young crowns for nutrients and moisture, weakening them before they establish. Thoroughly preparing the soil by incorporating amendments to a depth of 10 to 12 inches should be completed the season prior to planting.
The Step-by-Step Planting Process
Planting of the bare-root crowns should occur in the early spring, as soon as the soil becomes workable. The crowns are dormant and should be planted quickly after acquisition to prevent the roots from drying out. Start by digging a trench that is approximately 12 inches wide and 8 to 10 inches deep; a slightly shallower trench is advisable in heavy clay soil.
Inside the trench, build a small, continuous ridge or mound of soil and compost down the center, rising about 4 to 6 inches high. This mound provides a base for the crown and prevents water from pooling around the growth point. Place the crowns on top of this ridge, spacing them 12 to 18 inches apart, with the roots draped evenly down both sides of the mound.
The crown’s central bud should rest upright on the peak of the ridge before being covered. Initially, cover the crown with only 2 to 3 inches of the excavated soil, firming it gently around the roots. The remaining trench will be filled gradually over the course of the first growing season. This technique encourages the development of a deeper, more robust root system.
Essential Care During the First Season
Immediately after the initial planting, the crowns require a thorough watering to settle the soil and eliminate air pockets. Consistent moisture is necessary throughout the first growing season for successful establishment. The bed should receive about one inch of water per week, either from rain or irrigation, as drought stress can severely weaken the developing crowns.
As the first spears emerge and grow 4 to 6 inches tall, begin the process of gradually filling in the trench. Add another 2 to 3 inches of soil around the growing spears, being careful not to completely bury the emerging tips. Continue this gradual backfilling as the ferns grow taller throughout the season until the trench is level with the surrounding ground.
Weed control is an ongoing task that must be handled with care to avoid damaging the shallow, extensive root system. Hand-pulling weeds is preferred over deep hoeing to prevent accidental injury to the plant. Crucially, no harvesting should occur during this first year. All above-ground growth, known as ferns, must be allowed to develop fully to photosynthesize and store energy in the crown. Allow the ferns to grow until they turn yellow and die back naturally in the fall before cutting them down.