Asparagus is a highly sought-after perennial vegetable, prized for its tender spears. A well-maintained patch can produce for over a decade, making successful cultivation dependent on proper timing and meticulous site preparation. For gardeners in Tennessee, understanding the specific regional guidance is necessary to ensure the patch thrives. This article provides the information needed to establish a productive asparagus bed in the state.
Optimal Planting Timing in Tennessee
The most favorable time to plant asparagus crowns in Tennessee is in early spring, as soon as the soil becomes workable and before the risk of hard frost has completely passed. This period typically falls between late February and early April. Crowns should be planted when the soil temperature consistently reaches about 50°F, which triggers optimal root growth.
Planting dormant, one-year-old crowns is the preferred method, reducing the time until the first harvest. Gardeners should monitor local weather patterns rather than relying solely on calendar dates. Planting too early risks damage from late freezes, while planting too late hinders root establishment before summer heat.
Site Selection and Soil Preparation
Since asparagus is a perennial, the initial site selection must be permanent, as transplanting is not recommended once established. The site must receive full sun, meaning a minimum of six to eight hours of direct sunlight daily, as insufficient light reduces spear production. Asparagus develops an extensive root system, requiring deep, loose, and well-drained soil. Heavy clay soils and shallow sites should be avoided because they restrict root growth and increase the risk of crown rot.
Ideally, the soil should be a sandy loam with a slightly acidic to neutral pH, optimally between 6.0 and 6.8. Conduct a soil test before planting to determine if amendments are needed to adjust the pH or supplement nutrients. Amending the soil with generous amounts of organic matter, such as well-aged compost or manure, should be completed in advance to improve drainage and fertility.
The Physical Planting Process
Planting asparagus crowns involves preparing a trench to accommodate the root system. Dig the trench 8 to 12 inches wide and 6 to 10 inches deep, adjusting the depth based on soil type. Create a small mound or ridge of soil down the center of the trench to serve as the base for the crown.
Place the dormant, one-year-old crowns atop this central ridge, carefully spreading the roots out to drape down the sides. Space crowns 12 to 18 inches apart within the trench. If planting multiple rows, space them 3 to 5 feet apart to allow for maintenance and prevent overcrowding. After placement, cover the crowns with only 2 to 3 inches of soil, ensuring the buds point upward.
Establishing the Asparagus Patch
The first few years after planting are dedicated to root establishment rather than harvesting. After planting, the new bed requires consistent, deep moisture, especially during the first growing season. Water the soil deeply about once a week to a depth of one foot, preventing the crowns from drying out.
Weed control is a primary concern for young asparagus, as the plants are poor competitors against aggressive weeds. Use shallow cultivation and hand-weeding for control, ensuring the roots are not damaged by deep tilling. As the first-year shoots grow, gradually fill the trench with soil throughout the season until it is level with the surrounding ground, which protects the emerging crowns.
The most important rule for establishing a patch is the “wait period” before harvesting. No spears should be harvested during the first year of growth; this allows the crowns to store maximum energy reserves in the roots. In the second year, a very light harvest can be taken for about a week, but the spears must then be allowed to grow into ferns. Full, sustained harvesting for six to eight weeks should only begin in the third year and onward.