Choose the polytunnel cover material that is best for you: Lumisol Clear: Due to its clarity, clear polythene allows around 2% more light to enter your polytunnel than a diffused polythene cover. This extra light brings extra heat which can be a benefit during the early and late months of the growing season. More popular in northern and western regions where lower light levels and cooler temperatures naturally occur. Especially useful where an early start to the growing season is required, but where higher summer temperatures are not too detrimental. Lumisol Diffuse: Light-diffusing polythene films scatter natural light as it passes through the polythene film. This enables the light to penetrate deeper in to the plants canopy, as it hits the plant from all angles not just from the direction of the sun. This reduces the upper foliage shading the lower parts of the plant. The cloudy appearance of this polythene reduces the amount of light (mostly infra-red light) reaching your crop by around 2%. This reduction in IR light creates a slightly cooler daytime environment, up to 4°C lower at midday in mid-summer, which can be a considerable benefit to many crops especially in the sunnier parts of the UK. Opaque White: Produces shade and reduces daytime temperatures by only allowing around 65-70% light transmission. Ideal for crops that require shade and cooler temperatures such as nursery stock, ferns, and conifers. Also suitable for the overwintering of hardy shrubs and for general hardening-off. Widely used in agriculture to cover polytunnel livestock housing, and for general storage uses. Green/White (Blackout) : A black-out polythene with 0% light transmission. Especially formulated to meet the needs of the mushroom grower. Also used in conjunction with assimilated lighting to manipulate day length/duration. The green outer layer helps this cover blend in with the environment, whilst the white underside reflects artificial lighting to reduce light inputs. A black core layer ensures complete opacity (black-out) and contributes to the durability of the film.