The perennial vegetable Asparagus officinalis, often found growing wild along roadsides and abandoned fields, presents an appealing opportunity for gardeners. These wild colonies, which originate from escaped cultivation, can be successfully relocated to a domestic garden bed for better yields and convenience. Transplanting asparagus is a long-term gardening commitment, creating a productive bed that can last for decades, and requires meticulous preparation to establish successfully.
Optimal Timing and Selecting Wild Crowns
The timing of the transplant is paramount to the plant’s survival and establishment. Asparagus crowns must be moved only when they are completely dormant. This occurs either in late fall after the foliage (ferns) has completely died back and yellowed, or in the very early spring before new spears emerge. Moving a crown while it is actively growing will result in transplant shock and failure because the plant is expending energy on spear production rather than root maintenance.
When selecting a wild colony, look for strong, healthy plants that produced thick, dense ferns the previous season. The vigor of the fern growth directly indicates the energy reserves stored in the underground crown. Choose a crown that is at least a few years old, avoiding very small or weak-looking specimens. Inspect the area for any signs of disease or pest damage before extraction.
Preparing the Permanent Planting Site
The chosen destination must satisfy the long-term needs of this perennial crop. Asparagus requires a minimum of six to eight hours of direct sunlight each day to photosynthesize sufficient energy. Selecting a site that receives full sun exposure will maximize the plant’s energy storage capacity, leading to a robust and productive bed.
Proper drainage is non-negotiable, as asparagus crowns cannot tolerate “wet feet” and will quickly succumb to rot in saturated soil. A deep, loose, sandy loam is the ideal soil composition, allowing the extensive root system to penetrate deeply. Prior to planting, the soil should be generously amended with well-aged compost or manure to improve structure and fertility. Asparagus thrives in a slightly acidic to neutral environment, with an optimal soil pH range between 6.5 and 7.5.
Step-by-Step Crown Extraction and Replanting
Extraction must be performed with great care to minimize damage to the brittle, fleshy roots. Begin by digging a wide circle around the base of the selected fern, typically 12 to 18 inches away from the center. The goal is to lift the entire root mass, or crown, intact, as the roots contain the energy reserves the plant will need to recover.
Once extracted, the crown should be planted immediately into a prepared trench approximately 8 to 10 inches deep and 12 inches wide. Create a small, mounded ridge of soil down the center of the trench to serve as the base for the crown. Carefully drape the roots over this central mound, ensuring they spread evenly outward and downward, resembling the spokes of a wheel.
The crown should then be covered with only two to three inches of soil, just enough to anchor the roots. After backfilling with the initial layer of soil, gently tamp it down and give the newly planted crown a thorough watering. This immediate saturation helps settle the soil around the roots, eliminating air pockets.
Critical Care During the Establishment Phase
Following transplantation, the primary focus during the first growing season is to encourage a massive, healthy root system. The newly planted crowns require consistent moisture, especially during dry periods, to facilitate root growth and recovery. While regular watering is necessary, avoid waterlogging the trench, which would quickly lead to crown rot.
Weed control is paramount during this establishment phase, as young asparagus crowns compete poorly against invasive weeds. Hand-weeding around the base of the plant is recommended to prevent disturbing the fragile, shallow feeder roots. Avoid deep cultivation near the crowns, as this can easily damage the developing root system.
Do not cut down any spears that emerge in the first year; allow them to grow into tall, ferny stalks. These ferns are responsible for photosynthesis, generating the carbohydrates needed to replenish the crown’s depleted energy reserves. A light application of a balanced fertilizer or compost tea can be given once the ferns are actively growing.
Future Harvesting Guidelines
The most challenging aspect of transplanting asparagus is exercising patience. The traditional “three-year rule” applies to transplanted wild crowns, meaning no harvesting should occur in the first spring and often not in the second spring. This waiting period is necessary to allow the crown to fully recover from the stress of being moved and to build up the substantial root mass required for sustained production.
A light harvest can typically begin in the third spring after transplantation. Only harvest spears that are at least the thickness of a pencil, leaving any thinner spears to grow into ferns. The proper technique is to either snap the spear cleanly off at ground level or use a sharp knife to cut it just above the soil line.
Stop harvesting when the diameter of the emerging spears noticeably decreases, signaling that the crown is running low on stored energy. Allowing the remaining spears to develop into ferns is crucial, as they will spend the rest of the growing season gathering and storing energy for the following spring’s production. Established beds can be harvested for four to six weeks annually.