The best plants, fruit, vegetables and flowers usually fetch the best prices. But that can mean protecting the crops from wind, rain and extreme temperatures. It can also mean providing enhanced conditions with the most suitable light in terms of wavelength and intensity for growth, colour, flowering and fruiting. Polytunnels and plastics-clad houses are a cost-effective way of doing all that.
The choice of structure may be limited by space and site features, so start by making an assessment that includes additional details such as prevailing wind direction and speed. Consider the required height for the crops and access for machinery. Doors, ventilation, irrigation and transport should be designed in from the start. The type of construction and steel used will largely depend on strength requirements.
Cladding is the other variable factor and these days there is a wide choice on offer, each having properties that could significantly improve crop quality or simplify production. Cropping times can be cut and the requirement for growth regulators and pesticides reduced, even eliminated, by selecting the correct cladding to suit the purpose.
Although standard polythene is still available, most growers are now using the best they can afford from the wide range of "smart films". These contain polymers and additives for spectral modification that can benefit plant morphology or help reduce fungal diseases and aphid attacks.
There are also thermic films that provide frost protection and can be used over crops that would normally require a little heat, and as such may reduce heating costs.
It is important to remember that film thickness does not necessarily equal film strength, so check out the specification and test results of the films that you shortlist. Think too about end-of-life disposal.
Recognising that cladding is now a major and complex consideration, we have produced the Polytunnels product and suppliers table to detail a selection of the options available from leading manufacturers and importers based in the UK.
Most of the products are supplied by firms designing and constructing tunnels and houses, and are also available through trade and wholesale outlets.
Note The omission of any company or product does not imply criticism.
Supplier contact details
Agralan Sales 01285 860015; bpi.visqueen 01294 842000; Brinkman UK 01483 842123; Capatex 0115 978 6111; Citadel Polytunnels 01789 842689; Clovis Lande 01622 873900; DP Structures 01282 832870; Elite Tunnels 01386 648598; Fargro 01903 721591; First Tunnels 01282 601253; Five Star Polytunnels 01570 421580; Fordingbridge 01243 554433; Haygrove Tunnels 01531 633659; Keder Greenhouse 01386 49094; Lows of Dundee 01382 229251; McGregor Polytunnels 01962 772368; National Polytunnels 01772 799200; NP Structures (Northern Polytunnels) 01282 873120; Polybuild 01903 892333; Polytek Services 01622 721389; Premier Polytunnels 01282 811250; Pro-Tech Marketing 01905 451601; Rovero Systems 00 31 162 574574; Tildenet 0117 966 9684; XL Horticulture 01404 823044