How to Grow Calçots USA | Soil, pH & Growing Guide

Soil & Growing Conditions

Water: irrigated per traditional practice (Frontiers)

Quick Facts

At a Glance

Growth Stages

Harvest & Storage

When to pick: Harvested at one of two traditional windows: December for a sharper, more pungent early harvest, or February for a sweeter, less fibrous late harvest closer to the ideal calcot profile (Frontiers). Shoots are cut once earthed-up and elongated, with the blanched white base as the prized edible portion.

Diseases

Pests

Calçot, Field to Calçotada

Earthed up like a leek

As the second-year shoots grow, soil is mounded around them to exclude light -- the same blanching principle used for leeks, keeping the base white and encouraging the shoots to elongate.

One bulb, up to 25 shoots

Frontiers in Plant Science: a single dormant bulb, replanted for its second year, can resprout into between 1 and more than 25 slender shoots -- each one a calçot.

Timing changes the flavour

Harvested in December for a sharper, more pungent result, or held until February for a sweeter, less fibrous crop closer to the traditional ideal (Frontiers in Plant Science).

The calçotada tradition

An EU Protected Geographical Indication product of Catalonia, calçots are traditionally chargrilled whole over an open flame and eaten by hand at a calçotada -- the growing method exists specifically to produce this dish.

Grown mainly from one landrace

Most calçots come from the long-day 'Blanca Tardana de Lleida' landrace, replanted from dormant bulbs each August or September specifically for this second-year resprouting habit.

References

1. Frontiers in Plant Science (peer-reviewed journal) - Improving the Commercial Value of the 'Calcot' (Allium cepa L.) Landrace: Influence of Genetic and Environmental Factors in Chemical Composition and Sensory Attributes

   Calcots are the immature floral stems of second-year onion resprouts, mainly from the long-day 'Blanca Tardana de Lleida' (BTL) landrace of Allium cepa L. The traditional landrace produces between 1 and more than 25 resprouts ('calcots') per onion bulb, harvested in the plant's second year of growth. Bulb onions are replanted at a density of 32,000 plants per hectare, planting pattern 0.3 x 0.75m, at two possible times: mid-August (early planting) or late September (late planting). Soil: loamy texture, calcareous, between basic and slightly alkaline (pH 8.27-8.61), low organic matter, no electrical conductivity problems recorded. Harvested at two different times: December (early harvest, higher chemical/pungency values) or February (late harvest, sweeter and less fibrous, closer to the ideal sensory profile). Each field managed by farmers using their own customary traditional cultivation techniques for fertilization, irrigation, weed control and pest management -- no standardized disease/pest data given.

2. Specialty Produce -- Tier 2, used only for the earthing-up/blanching technique and EU Protected Geographical Indication status not covered by the Tier-1 journal source, not contradicted by it - Calcot Onions Information and Facts

   Calcots are grown from onion bulbs allowed to remain dormant from the previous season and replanted the following late summer. As the resprouted stalks grow, they are covered with dirt (earthed up) to keep the base white and elongate the shoots -- the same blanching principle used for leeks. Favoured for a mild, sweet flavour and tender texture. Registered with an EU Protected Geographical Indication, certifying they are grown according to traditional methods from their geographical origin in Catalonia, Spain.

2 independent sources are cited for this crop. Where they disagree - soil pH is the clearest case - every figure is preserved rather than averaged into false precision.