Cauliflower Production Guide

Site Selection

Cauliflower grows best in medium to heavy clay loam soils with good water-holding capacity. Sandy soils may be used but will require more frequent irrigation and higher levels of fertilisation. The ideal soil pH is between 5.5 and 6.0, with levels closer to 6.0 recommended for sandy soils. It is highly advisable to take soil samples for analysis before planting.

Cauliflower responds very well to compost-enriched soils. Ploughing should be done to a depth of 30–35 cm, ensuring any old plough pan is broken up. Ripping followed by discing is also effective in preparing the tilth. The soil should not be too cloddy or too fine. During winter, if possible, plant on north-facing slopes to benefit from increased soil warmth.

Spacing

During the rainy season, cauliflower should be planted on raised beds to improve drainage. In winter, planting on the flat is preferred.

If using beds:

• Beds should be 1.5 metres centre to centre.
• Plant 2 rows on top of the bed, spaced 60 cm apart, with 40 cm between plants in the row.

If planting on the flat:

• Rows should be 60 cm apart with 40 cm between plants in the row.

Target plant populations should range from 33,000 to 40,000 plants per hectare.

Fertilizer

Apply a balanced basal fertiliser such as High C before planting. This can be applied using a Vicon spreader (for flat plantings) or a ridger-type applicator (for beds). Fertiliser may also be cupped by hand into the planting holes, but it must be well mixed into the soil to avoid root burn. Based on soil analysis and soil type, basal fertiliser rates can range from 500–750 kg per hectare.

Cauliflower generally requires 400 kg/ha of Ammonium Nitrate (AN), split into three applications between weeks 2 and 6 after transplanting. For winter plantings, Calcium Nitrate is recommended instead of AN, as it is quicker acting in cool soils. Cauliflower is particularly susceptible to Boron deficiency, which causes Hollow Stem, so regular monitoring is essential.

Seedlings

Transplanting seedlings is the most practical method for establishing a cauliflower crop. Healthy, uniform seedlings create a strong foundation and improve uniformity at harvest, reducing labour costs.

Transplant speedlings as soon as possible after removing them from trays to prevent the fine hair roots from drying out. Plant into pre-irrigated soil that has been brought to field capacity. After transplanting, apply a light irrigation to settle the soil and eliminate air pockets between the plug and the soil.

Irrigation

Irrigation is critical during the dry winter months. Overhead sprinklers are the most commonly used method, followed by flood irrigation and, more recently, drip irrigation.

During summer cultivation, maintaining consistent soil moisture is essential, as water fluctuations can lead to Hollow Stem. A total of 600–750 mm of water is typically required to produce a good crop.

As the plant grows and the curd begins to form, water requirements increase. Using an evaporation pan can help monitor water demand. On medium to heavy clay soils, irrigate when about 25% of the available water has been used.

Rotations

Avoid planting cauliflower directly after any other Brassica crop, such as cabbage, broccoli, or rape. Rotate instead with a legume or root crop to break disease cycles and maintain soil health.

Pests

Diseases

Weeds

Chemical Reference