The seeds for wholehead are grown by specialist plant raisers. They have the all-important job of growing the seeds into sturdy seedlings. Over the years a variety of seeds have been developed to cope with different climates, seasons and soil types.
The seeds, which are coated to aid germination, are planted in small blocks of compost and then covered with sand.
The seedlings are carefully grown in large greenhouses in temperature-controlled conditions. They take about 3 weeks to reach the size where they are ready to be planted in the field. The plant raisers work is now done and they hand over the precious seedlings to the various salad crop growers around the country.
Before the seedlings are planted, specialised machinery goes to work to prepare the land. This ensures the young plants have the best possible start.
A lot of care and attention is put into the planting of the seedlings. A skilled planter ensures that the compost blocks go into the soil a set distance apart, and a supervisor will also check the field to make sure the seedlings are correctly planted.
While they are growing, salad leaves are carefully tended and nurtured to prevent disease and damage. Farm managers walk the crops every day checking their progress.
Nutrients and irrigation are required to maintain the best possible growing conditions and these are applied under a carefully managed process. This crop management system produces a healthy and consistent quality at harvest.
Most farms use sophisticated weather stations to constantly monitor conditions likely to produce high levels of disease. With this early warning system, appropriate action can be taken to avoid loss or damage of the crop, such as the protection of salads with vast carpets of mesh anti-thrip nets laid on to wire hoops across a field (a thrip is one of the tiniest known pests).
All these processes follow the protocol laid down in the Assured Produce Scheme - designed by growers and retailers to regulate crop management procedures for safe food production.