Education

Plants grown in modern production facilities are “all female” F1 hybrids which enable earlier cropping and are suitable for more intensive production systems. They also provide enhanced tolerance to plant pathogens such as mildew, effectively reducing growers’ reliance on intensive fungicidal spray programmes and creating a more favourable environment for the establishment of biological control agents.

Plants are usually propagated by specialist plants raisers in November/December and transferred to production glasshouses in December/January.

Fruit picking begins in late January/February and is continuous for the life of the crop.

Most growers now replace crops at least once and sometimes twice, enabling them to supply good quality produce throughout an extended season. Through careful management the break in cropping can be restricted to less than three weeks, and by staggering the timing of replants, many growers now have productive crops in their glasshouses from January to October.

Crops are grown in high quality Venlo-style glasshouses with computer controlled environments enriched with carbon dioxide to improve growth and yield. Day time temperature is maintained at a minimum of 21ºC via hot water pipe systems and the atmosphere is automatically ventilated at 23 – 24ºC.

Plants are grown in artificial, inert substrates, the most common being rockwool. These substrates are sterile and free from inherent disease problems. Nutrients are applied as liquid feeds through computer controlled irrigation systems.

Cucumbers are usually grown by the cordon training technique:

• The main stem is trained up a vertical string that is tied to a horizontal support wire positioned about 2m above the ground. Side shoots are removed from the main stem until it reaches the support wire.
• Three strong lateral shoot are then selected and the main growing point is removed.
• The side shoots are allowed to cascade downwards to a length of about 1m and their growing points are removed to encourage “sub-lateral” shoot development.
• Crop is performed every 7 – 14 days when any additional unwanted side shoots are removed.lants grown in modern production facilities are “all female” F1 hybrids which enable earlier cropping and are suitable for more intensive production systems. They also provide enhanced tolerance to plant pathogens such as mildew, effectively reducing growers’ reliance on intensive fungicidal spray programmes and creating a more favourable environment for the establishment of biological control agents.

How peppers are commercially grown in the UK:

In 2024, in accordance with CPGA estimates, commercial pepper crops cover an area of approximately 80 hectares in Great Britain.

When does the season start?

The UK pepper growing season starts with sowing the seeds in November and planting the crops in December and January into the glasshouse. Pepper growers work to produce fruit consistently for ten months of the year, using modern commercial varieties.

As growers are reliant on high light levels, peppers are harvested from February to November in the UK. Plants are vertically grown, inside technologically advanced glasshouse facilities.

How are pepper crops grown?

Most “conventional” peppers crops are grown in soil-less hydroponic growing systems. The pepper plants are grown in slabs of inert growing material such as rockwool or coco fibre and planted in raised troughs (hanging gutters) which offer excellent drainage control, disease reduction, and ventilation for increased production.

A number of growers grow pepper crops in soil and in compliance with Soil Association Organic standards, but this makes up only a small proportion of UK-grown crops.

State-of-the-art computer controlled climatic systems in the glasshouses, automatically adjust in relation to internal and external conditions and help to manage the growing conditions of temperature, feed (nutrients), and carbon dioxide. The latest irrigation and natural gas heating systems are used to water and heat the crops. This includes carbon dioxide extraction from CHP (combined heat and power) units for improved plant growth and fruit quality.

Pepper growers use many environmentally friendly growing methods, including the conserving of energy, water recirculation, and an integrated approach to crop management that uses biological control (introducing natural predators to control potential pests). Native bees are used to pollinate flowers and enhance fruit quality.

From a pepper flower, it takes approximately 30-40 days to grow a mature green pepper (depending on the time of the season) with a further 3 weeks to ripen into other colours. The colour the pepper ripens to will depend on the variety planted.

Plants are trained up strings to optimise the light each plant head receives. Also, side shoots are removed to ensure the plant makes new fruit in the length.