Asparagus is a perennial crop commonly started from one-year-old crowns, but it can also be successfully grown from seed. Starting from seed introduces greater genetic diversity, which can lead to plants with increased vigor and resilience. This method requires patience, as the time until the first harvest is longer, but it offers a rewarding experience in cultivating this long-lived vegetable.
Preparing Asparagus Seeds for Planting
Asparagus seeds possess a hard seed coat that inhibits water absorption, leading to slow and variable germination rates. To overcome this natural barrier, seed preparation is recommended before sowing, as it significantly improves the speed and consistency of sprouting.
A simple method involves soaking the seeds in warm water for 24 to 48 hours immediately prior to planting. The warm water softens the outer shell, allowing moisture to penetrate the embryo and initiate growth. The water should be refreshed at least once during this time.
Determining the Number of Seeds Per Hole
The number of asparagus seeds to plant in a single spot hinges on mitigating the risk of low germination. Given the unpredictable nature of seed viability, it is standard practice to sow multiple seeds. Planting two to three seeds per intended location hedges against failure, ensuring at least one seedling emerges to establish a permanent plant.
This strategy accounts for seeds that fail to sprout or lack the strength to survive the early growth phase. Seeds should be sown shallowly, typically no deeper than one-half inch below the soil surface. Sowing at this depth provides the emerging sprout with enough energy to push through the soil while being protected from drying out.
Planting in multiples is a temporary measure designed to guarantee the establishment of a single, healthy plant. The goal is never to encourage multiple mature plants to grow together, as this leads to excessive competition.
Spacing, Germination, and Thinning
Once the seeds are sown, proper spacing must be maintained to allow for the extensive root system that mature asparagus plants develop. Each planting hole should be spaced approximately 12 to 18 inches apart within the row, providing ample room for the crowns to expand. Adequate spacing is important for the long-term health and productivity of the perennial patch.
Asparagus germination can be a slow process, often taking anywhere from two to eight weeks, even with proper pre-soaking. The variability depends on consistent soil temperature and moisture levels. Gardeners must remain patient, ensuring the seedbed does not dry out but also avoids becoming waterlogged.
When the seedlings have emerged and grown to a height of about two to three inches, the process of thinning must occur. The objective is to reduce the multiple sprouts in each hole down to a single, dominant plant. Carefully remove the weaker seedlings by snipping them off at the soil line, leaving the most vigorous plant intact. This action eliminates competition, allowing the remaining plant to focus energy on developing a strong, healthy crown.