Asparagus is a perennial vegetable prized for its tender spears, typically harvested in early spring. Many home gardeners wonder if they can use fresh produce purchased from the grocery store to start their own patch. Asparagus establishes an underground system that continues to produce for decades, making its cultivation different from annual vegetables. This guide addresses the question of planting store-bought asparagus and provides the proper method for establishing a successful, long-term bed.
The Verdict: Why Store-Bought Spears Will Not Grow
The short answer to whether you can grow asparagus from a grocery store spear is no. The spears sold in stores are the young, harvested stems, severed entirely from the root system that provides life and energy. These temporary shoots lack the structure necessary for long-term survival and regeneration once cut.
A store-bought spear might remain fresh if kept in water, but it does not contain the complex root structure, known as the crown, required to establish a permanent, perennial plant. Without the energy reserves stored in the crown, the severed spear cannot develop a functioning root system to sustain itself. Planting the fresh stems will only result in the spear rotting in the soil rather than sprouting a new plant.
Understanding Asparagus Biology: Crowns Versus Spears
The distinction between the spear and the crown is fundamental to successfully growing asparagus. The spear is the above-ground shoot that is consumed. If the spear is not harvested, it rapidly develops into tall, fern-like foliage responsible for photosynthesis during the growing season.
The crown is the perennial, underground root structure composed of fleshy rhizomes and buds. This crown is the energy storage organ, accumulating carbohydrates throughout the summer and fall to fuel the next spring’s spear production. The crown is the part of the plant that must be planted to start a new asparagus bed.
While asparagus can be started from seed, this method requires an additional year of patience for seedlings to develop into a crown. Most gardeners choose to purchase one-year-old crowns, which are dormant roots that already have a head start. These established crowns allow for a harvest to begin a year sooner than starting from seed.
The Proper Way to Start Asparagus
The correct approach involves planting one-year-old dormant crowns in early spring, typically two to four weeks before the last expected frost. Asparagus is a long-lived perennial, often remaining productive for 15 to 30 years, so site selection is a permanent decision. The location should receive full sun (six to eight hours of direct light daily) and must have well-drained soil, as the roots cannot tolerate sitting in water.
Preparation of the bed involves digging a trench approximately 12 to 18 inches wide and 6 to 8 inches deep. The soil should be loosened to a depth of 12 to 15 inches to allow the extensive root system to grow properly. Incorporating well-rotted compost or aged manure into the trench bottom creates a nutrient-rich base.
To plant the crowns, create a small mound of soil, about two inches high, along the center of the trench. The crowns are placed on top of this mound, with the fleshy roots spread out evenly over the ridge. Spacing the crowns 12 to 18 inches apart gives each plant adequate room to develop.
The crowns are initially covered with only two inches of soil, and the trench is watered well to settle the soil around the roots. As the first spears emerge and the plants grow during the first season, additional soil is gradually added to the trench. This process continues until the trench is filled to ground level, ensuring the crown is ultimately buried about four to six inches below the surface.
Patience Is Key: Establishing the Asparagus Bed
Asparagus requires a significant investment of time, as the first two to three years following planting are dedicated to establishing the root system. During the first year, allow all spears to grow uninterrupted into their mature, fern-like foliage. This fern growth photosynthesizes and generates the energy needed to build up the crown’s carbohydrate reserves.
Maintaining healthy fern growth throughout the summer and fall is necessary for a successful future harvest. The ferns should remain in place until they turn completely brown in late fall or early spring, then they can be cut back to the ground. This dormancy period allows the plant to rest and prepare for the next season.
The first harvest should not begin until the third year. Even then, the harvest period must be limited to a short duration, typically two to four weeks, to avoid depleting the crown’s energy stores. In subsequent years, a mature bed can be harvested for a longer period, generally six to eight weeks, before the remaining spears are allowed to grow into ferns to recharge the plant.