Young plants are potted into liners using a potting machine within the propagation unit, and transferred to the adjacent liner unit. The liner unit consists of 4500sqm of Efford Sand Beds under glass, a further 5000sqm glasshouse beds with overhead irrigation, and an additional 1000sqm of tunnels and outside beds. Liners are grown in the area which is most suitable to their growing requirements. The liner unit is controlled by a computerised environmental control system to provide the optimum environment, and integrated pest management is employed within the unit. The unit can house 700,000 lines at any one time and can produce 1, 300, 000 liners a year at full capacity.