A Polytunnel can give you a Mediterranean or even Tropical climate right in your garden. Grow exotic fruit and vegetables and enjoy traditional fruit and vegetables out of season.

Increase Your Growing Season

Because a polytunnel encloses a larger volume of air than a greenhouse, a polytunnel stays warmer longer, providing a frost free environment for a greater proportion of the year. For an even longer growing season, bubble insulation can be used or the polytunnel can be heated.

Create Shelter

Another big advantage is shelter from wind and rain – for your plants and you! You can buy a large polytunnel for the same price as a small green house.

Robust & Economical

For the same price as a small greenhouse you can buy a large polytunnel. Polytunnels are also a safer alternative to glass houses. The polythene cover lasts 5 to 7 years and replacement covers generally cost about 20% of the complete polytunnel i.e. less than 4% of the tunnel price per year.

Tanalised timber posts are supplied for each end of the frame and the polythene cover is attached to these. Hinged steel doors are provided for each end.

Complete Polytunnel Kits from Knowle Nets

Supplied as a complete package consisting of steel frame, polythene cover, timber door frames, two hinged doors and full instructions. We supply 5 widths; 2.0m (6½ft), 2.5m (8ft), 3.0m (10ft), 3.5m (11½ft), 4.0m (13ft). The Hoop is spacing 1.2m (4ft) for a strong frame.

Garden Polytunnel
Poltyunnel clamp

The Framework

We use steel for the framework as this gives the strength required at an economical cost. The wind resistance of a Polytunnel is much higher than a Fruit Cage. We heavily galvanise the inside and the outside of the tubing to give it a long life. The main framework is 25mm (1 inch) diameter and the foundation tubes are 32mm (1¼ inches) with a polythene retensioning system. The hoops are spaced at 1.2m (4 feet) intervals, connected by tubes along the ridge. The four corners also have brace bars at a height of about 0.9m (3 ft).

Polythene Cover

Our standard cover is a heavy 150 micron Thermal polythene with UVI inhibitors giving a life expectancy of approximately 5 to 7 years. It has been designed specifically for the UK where low light levels are common. Light is transmission approximately 88%. As an option the cover can be upgraded to 180 micron UV blocking polythene which has all the advantages of our standard film but also blocks ultra violet light. The major advantage of this is for organic growers because it reduces Mildew, Botrytis and insect attack as insects only see in ultra violet. The frame is lined with 20mm wide anti hot spot tape which insulates the polythene from the steel tubing to give more even polythene wear, and extend the life of the polythene.

Garden Polytunnel

7ft high polytunnels are available in 5 widths: 2m, 2.5m, 3m, 3.5m, 4m

Made from 25.4mm diameter galvanised steel with a hoop spacing of 1.2m, the package includes:

  • Ground Tubes
  • Polythene Cover
  • Timber Door Frames
  • Hinged Steel Doors (at each end)
  • Anti Hotspot Tape
Tunnel Cloches

These are available in 2 sizes: 0.45m high x 0.8m wide, 0.9m high x 1.2m wide

Made from aluminium tubing which will not rust. Choice of four covers:

  • Fleece
  • Polythene
  • 6mm Mesh Net
  • 19mm Mesh Net
Cloche Tunnel
Cloche Parts
Polytunnel and Cloche Parts

We have a stock of replacement parts and accesories for all of our polytunnel and cloches including:

  • Polytunnel & Cloche Film
  • Polythene Repair Tape
  • Anti Hot Spot Tape
  • Ventilation
  • Crop Bars
  • Timber Base Rail Fittings