Asparagus is a highly valued perennial vegetable, providing some of the first fresh produce of the spring. Unlike most vegetables replanted annually from seed, asparagus is typically established using one-year-old root structures called crowns. Growing this long-lived crop from “scraps” involves asexual propagation, specifically the division of an existing, mature crown. This technique bypasses the multi-year process of starting from seed, offering a cost-effective and faster way to expand an asparagus patch by multiplying existing stock.
Identifying Viable Asparagus Scraps for Propagation
The term “scraps” refers to pieces of a mature, living root system, including the crown and attached rhizomes. The most successful method involves carefully digging up and dividing an established crown, the central, woody part of the plant where spears emerge. A mature crown, often five years old or more, becomes a dense mass of fleshy roots that can be split into multiple new plants.
Each resulting scrap must contain a portion of the main rhizome and at least one or two visible, plump buds, often called “eyes.” These buds are the growing points for new spears and are found on the crown’s top surface. Propagating from the cut bases of harvested spears, such as those bought from a store, is ineffective because they lack the necessary crown tissue. Choose a robust parent plant producing thick, healthy spears, as this vigor will be passed on to the new divisions.
Preparing the Planting Site and Scraps
Preparing the permanent planting site is crucial, as asparagus can remain productive for 20 years or more. Asparagus requires full, direct sunlight to maximize energy storage in the roots. The soil must be well-drained; fleshy roots rot easily in soggy conditions. Amending heavy soil with coarse sand or organic matter, like compost, is necessary.
The ideal soil pH ranges from 6.5 to 7.0. Before planting, excavate a trench 12 to 18 inches deep and about a foot wide to accommodate the sprawling root system. This deep trench allows for gradual filling, encouraging the crown to set deep roots. After dividing the crown, allow the newly cut root surfaces to “cure” for a few hours in a shaded, dry area. This brief drying period helps the cuts callous over, reducing the risk of fungal infection and rot.
Planting and Initial Establishment
Planting the prepared crown divisions must be done carefully to ensure proper root orientation. Build a small, firm mound of soil or compost in the bottom center of the trench. The crown is placed on this mound, allowing the roots to drape evenly downward and outward, like the legs of a spider. Scraps should be spaced 15 to 18 inches apart to give each new plant ample room to develop.
Initially, cover the crown and spread roots with only two to three inches of fine soil or compost, ensuring the visible buds are just barely covered. Immediately after planting, deep watering is necessary to eliminate air pockets and settle the soil firmly around the roots. Apply a protective layer of organic mulch, such as straw or chopped leaves, over the planting area to retain moisture and suppress weeds. The establishment phase requires consistent moisture, especially during dry spells, to support root development.
Managing the Asparagus Patch for Long-Term Yield
Weed management is important for a successful asparagus patch, particularly in the first few years, as the shallow crown cannot compete well for nutrients and water. Hand-weeding is recommended over using a hoe, which can easily damage the developing crowns and lateral roots. Throughout the growing season, emerging spears are allowed to grow into tall, fern-like structures.
These mature ferns photosynthesize and store energy reserves in the crown, fueling the following spring’s harvest. Allow the ferns to remain until they naturally turn yellow and die back in late autumn, indicating nutrient transfer to the roots. After the foliage dies back, cut it down just above the soil line and remove it to prevent pests and diseases from overwintering. The first true harvest should not occur until the third spring after planting, allowing two full seasons for the crown to build energy reserves. Once established, the patch can be lightly harvested for four to six weeks in the spring.