Cauliflower propagation is from seed.
Direct seeding can be done to grow cauliflowers, although this is not the most common practice of commercial farmers as this does not create the most uniform crop and external weather conditions vary and can cause delay in establishment. Plant seeds 12 mm to 15 mm deep and try to keep depth uniform for a uniform crop.
The most common planting method is to plant nursery-reared cauliflower seedlings. Cauliflower seeds are planted into seed trays and kept indoors and reared in greenhouses at 20°C and a high relative humidity and planted out 30 to 35 days after sowing when they are about 15 cm tall and have developed five to six leaves. Cauliflower planting is normally done by hand, but some of the larger commercial producers’ plant using mechanised planters.
Plants should be spaced 50 cm apart in rows that are 60 cm apart. Try to have around 30 000 plants per hectare. Farmers also plant cauliflowers in tram lines with a slightly wider access row every two rows. Tram lines can be planted with 40 cm between plants in the row and 50 cm between the rows and 60 cm to 100 cm work lanes between the tram lines.
Although this is not the most popular way of cultivation, cauliflower seeds can be directly planted throughout the year as long as the temperature ranges remain above 15°C. Do not plant in cold temperatures below 10°C as this makes germination difficult.
Planting of cauliflower seedlings is done throughout the year except in very hot or very cold periods or areas. So in most of South Africa avoid planting between May and mid-August as a rule because of the winter cold. Plant only strong uniform seedlings as this will result in uniform growth and shorter harvest times.
Depending on the cultivar and the weather the growth from the planting of cauliflower seedlings to maturity is between 8 and 12 weeks. Some cultivars of Cauliflower can be ready in as short a time as 6 weeks from the planting of strong well-developed seedlings if conditions are ideal.
The best practice is to follow the guidelines given by your advisor based on the results of your soil samples and on the recommendation provided for the crop type you will be planting.
Cauliflower likes a good supply of nutrients and for its relatively short growing period requires an above average fertilizer application
Before planting apply 250 kg to 300 kg per hectare of an NPK mixture like 3:1:5 (35) and work this into the topsoil of the plant area. Once the new seedlings have settled, about ten days after planting, side dress with 200 kg to 250 kg per hectare of 3:1:5 (35) along the plant rows and irrigate into the soil. Repeat this at 18 to 21 days after planting and again at about 30 to 35 days after planting.
This should be sufficient for the crop to mature. Cauliflower leaves should be a healthy dark green and if signs like pale green or even yellowing leaves manifest this could mean a further application is required.
Make sure the soil is irrigated before planting the cauliflower and again right after planting for young plants to settle in well. Do not over irrigate as this can leach the first nutrients applied from the new plant's root zone. For this about 10 mm the day before and again 10 mm right after planting should suffice.
Thereafter 15 mm to 20 mm per week for the first two weeks then an average of 25 mm to 30 mm per week unless temperatures are higher, then this can be increased to 35 mm to 45 mm per week.
By Louise Brodie