Asparagus is a perennial vegetable arising from a root system of fleshy rhizomes known as the ‘crown’, which has long feeder roots that can grow to a depth of 1.5 - 2 metres. Since asparagus is a deep-rooted crop, soils need to be well drained. Alluvial loams, peaty soils and sandy loams are the most suitable soils for growing asparagus.
In spring the asparagus crown sends up shoots (spears), which are the edible portion of the plant. Spears continually emerge from the soil and can reach their marketable length of 25 cm in 24 hours if humid conditions prevail.
In the first season spears are only harvested for three to four weeks, with the main objective being to strengthen the plant through maximum fern development and maximum crown growth. The fern stage is very important to the plant as the ‘leaves’ photosynthesise and produce energy, which is then transported back to the crown where it is stored for the following season’s growth. Prolonged harvesting or stress can impact on the following year’s yield potential if the plant is not allowed to progress to the fern stage.
The asparagus fern dies down between April and May as the plant undergoes a natural dormancy period over winter. The debris from the fern is usually slashed and mulched back into the soil, with care taken not to damage the crown.
Click here to download the Asparagus Growing Cycle diagram.