Home gardening has led many people to explore ways to grow new plants from store-bought produce. This curiosity is common for highly prized perennial vegetables like asparagus, a spring delicacy that returns season after season. While the idea of simply planting a spear to start a patch is appealing, establishing a permanent, productive patch requires understanding the specific biology of the plant and a different approach than simple kitchen scrap gardening.
Why Store-Bought Spears Cannot Regrow
The fundamental reason a grocery store asparagus spear will not become a permanent plant lies in its anatomy. The spear is the harvested stem, or shoot, that emerges from the ground in spring. This shoot is cut above the crown, the underground structure responsible for the plant’s perennial life cycle. The crown is a mass of fleshy roots and a rhizome that contains the energy reserves and buds necessary to produce new spears year after year.
A harvested spear lacks this complex root and bud system. It has no way to anchor itself, store sufficient energy, or initiate the perennial growth necessary for survival. Although the spear is alive when purchased, it is essentially a severed part of the parent plant. It cannot regenerate a viable crown, which is the only structure that allows the plant to go dormant in winter and return for a decade or more of harvests.
The Short-Term Sprouting Method
Despite the impossibility of establishing a permanent patch, the asparagus spear can exhibit temporary growth, often called the “water trick.” This method involves placing the cut ends of the spears into a shallow container of water, similar to storing cut flowers to maintain freshness. The spears should be kept upright and placed in a cool location.
Within a few days, the spear may begin to sprout small, fern-like shoots from its tip, a process called “ferning out.” This temporary growth is the spear attempting to continue its life cycle using its limited energy reserves. The sprouts are not the start of a root system and are usually not suitable for eating. The main spear will eventually degrade and rot, meaning this novelty method only prolongs freshness briefly and offers no sustainable harvest or long-term plant.
Establishing a Permanent Asparagus Patch
Creating a perennial asparagus bed that produces for 15 to 20 years requires planting dormant, one-year-old crowns. These established root systems bypass the slow process of starting from seed, leading to an earlier harvest. The site selected must be in full sun and feature deep, well-drained soil, as asparagus roots extend deeply and are susceptible to rot in waterlogged conditions.
Preparing the planting bed involves loosening the soil to a depth of 12 to 18 inches and amending it heavily with organic matter to ensure good drainage. Asparagus prefers a slightly alkaline soil pH, ideally between 6.5 and 7.5. The crowns are planted in a trench, typically 6 to 12 inches deep, depending on the soil type.
Within the trench, small mounds of soil are formed, spaced about 12 to 18 inches apart. The crown is placed atop each mound, with its fleshy roots carefully spread out over the sides, resembling a miniature octopus. Initially, the crown is covered with only two to three inches of soil. The trench is gradually filled as the spears grow throughout the first season.
Patience is necessary for a successful asparagus harvest, following the principle known as “sleep, creep, leap.” In the first year, the plant “sleeps,” focusing energy into developing a robust root system, and no spears should be harvested. The second year, the plant “creeps,” continuing to strengthen its crown, and only a light harvest for a week or two is recommended.
The full, sustainable harvest begins in the third year, when the plant “leaps” into full production with an established root system. The harvest window typically lasts six to eight weeks. Spears are snapped off or cut just below the soil line when they reach six to nine inches in length. After the harvest period, remaining spears must be allowed to grow into tall, fern-like foliage to photosynthesize and replenish the crown’s energy stores for the following spring.