12ft Wide Polytunnel

A 12ft wide polytunnel will easily allow you to have one central bed and a further growing bed on each side - a layout that can really maximise the use of space while making it easy for the gardener to get around. If you are taking the next step on your journey towards a more sustainable way of life then a 12ft polytunnel could be perfect - big enough to grow a quantity of food but not so big that it becomes overwhelming in a domestic setting, on an allotment or in a community garden.

Check out 'What's in the Kit' to find out exactly what is included in your purchase of a 12ft wide polytunnel, then scoot on over to our accessories sections to see what added extras you may wish to include. Crop bars and staging will help you make the most of your space, while you can optimise your tunnel to meet your particular needs with things such as base rails and sliding doors. Even better - the more extras you include, the more you can save with our fantastic bonus save offers. Just pop everything in your basket to find out how much you can save on your ideal 12ft wide polytunnel.

Intro

All Our Prices Include VAT FREE Delivery 14 Day Money Back Guarantee

Tech Specs

The 12ft (3.66m) wide Polytunnel is another very popular Domestic option, ideal for the larger garden or allotment. On this width the straight sides give you ample room for staging, increasing your growing potential no end. Like all of our Domestic models, it comes with 'real' doors at each end, ensuring good air circulation.

Technical Specification

Width 12ft (3.66m)
Hoop Spacing 5ft (1.53m)
Overall Height 7ft 7in (2.31m)
Straight Side 3ft 3in (0.99m)
Head Room (15cm from side) 4ft 8in (1.42m)
Hoop Diameter 1in (25.4mm) (1¼in (35mm) on Super)
Steel Specification E370 Galv High Tensile
Door Opening Width 2ft 3in (0.69m)
Door Opening Height 6ft (1.83m)
Distance over Hoop 22ft 8in (6.90m)
Door Frame 3in x 2in (75mm x 47mm)
Inner Door 2in x 2in (50mm x 50mm)
Base Rail 3in x 2in (75mm x 47mm)

Instructions

We have four construction guides for our 12ft Wide Polytunnel Model.

12TR/12STR for polytunnels who require the cover to be buried in a trench. 12BR/12SBR for polytunnels that have Base Rails eliminating the requirement for digging a trench.  The 'S' denotes whether the Polytunnel has been upgraded to 35mm Hoops.

If you are experiencing problems with your polytunnel construction, our construction team are available to answer your questions and help in whatever way they can. Simply call 01282 601253 on week days between 9am-5pm...PLUS weekend cover on 07801 601253, between 9am-5pm or contact us. Alternatively, you can visit our construction resources website at polytunnels.co.uk.

We haven’t stopped there, we know many people build their polytunnels at the weekend or over a bank holiday when our office is closed, so we have also produced  a series of Polytunnel Construction Videos. This collection of videos can be viewed anytime, on your home computer, and even your phone for when you are in the thick of things constructing your polytunnel.

Sophie
Product Name
Verified order

It's amazing. It took longer than suggested to put up but my Dad and I managed it and it is fantastic. The plastic is easy to tension and it looks great too.

Murdoch McCracken
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Verified order

Have already put in my raised beds and very pleased

Joe McTernan
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Verified order

High quality and lots of extras to support the novice have a successful start to poly tunnel life.

Mike Edge
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Verified order

Great quality product, extremely sturdy.

C J Featherstone
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Verified order

Easy to use and very informative website. Speedy delivery. Looking forward to building and using our new Polytunnel ASAP!

Fionagh Harding
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Verified order

I love my tunnel; all I've had to do is provide the elbow grease, everything else has been thought through with care and attention to detail so that the finished tunnel will be perfect if the instructions are followed.

C J Featherstone
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Verified order

Our kit arrived within two days of placing the order. Very informative booklet and easy to access 'bite-size' videos guiding you step-by-step through construction. We purchased an upgraded version of our chosen tunnel, with belt, braces and safety pins as we live in a very exposed mountainside location, but having watched the video of a First Tunnel Poly Tunnel in a storm force gale on a cliff top, we have every confidence that ours will be fine! The 'Lucky Pack' that came with it includes everything you need to learn how to get maximum results from your poly tunnel. We are really looking forward to completing ours and starting our poly tunnel growing adventure!

Alan Hockley
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Verified order

Good quality product. Can't wait to start growing in my polytunnel!

John
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Verified order

A good product with everything arriving in good time and in good condition.

David Oliver
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Verified order

Great product, good quality

Adele McRae
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Verified order

High quality product, robust enough to withstand the weather in the Cairngorms area of Scotland.

Customer
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Verified order

HAVE'NT PUT THE TUNNEL UP YET BUT HAPPY SO FAR WITH THE SERVICE I EXPECT IT TO BE EVERYTHING I WAS HOPING FOR

Cobi Snelson
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Verified order

Extremely good quality - very well made.

Customer
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Verified order

Quality item. Looks strong and good quality although we have not put it up yet.

Karen Utting
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Verified order

ordering and delivery were great and very easy. Have yet to construct the polytunnel but have read the instructions which are clear to follow. I know that if I get into trouble there is online support.

Lynn Williams
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Verified order

I already have the 24ft version and the quality is great. we need extra growing space now so going for the longer one as an addition. Always get the largest one you can fit because you may need it in the future.

What's In The Kit

We supply Timber Hinged Doors at each end, Anti Hot Spot Tape, Timber Base Rails and of course the Framework to support our 200 micron Smart Clear Polythene cover.  

Timber Base Rails have been pre-selected as they offer an easier method for installation with a tensioning facility that creates a much tighter cover. Other 'Ground Fixing' methods and useful additions such as Sliding Doors, Ventilation, etc, can be added, please see our Optional Extras.

  1. Foundation Tubes
  2. Hoops
  3. Central Ridge
  4. Door Rails x 2
  5. Corner Stabiliser Bars x 4
  6. Hinged Doors & Frames x 2
  7. Anti Hot Spot Tape
  8. Smart Clear (200 Micron Polythene)
  9. Timber Base Rails

Options & Prices

Select the options below in order to configure your Polytunnel and when you’re happy, press "Add to basket"

Select Length

Select Type Of Cover

Help Me Choose

Your first big decision when choosing a Polytunnel is almost always..."What size is ideal?". But there's other important factors to take into consideration..."What type of cover do I want?". It might not sound like something to give a lot of thought to, but the cover you choose will affect your day-to-day Polytunnel management, what and how you grow. We have 4 options to choose from...

Super Therm

Our most popular polythene cover incorporates an additive that increases its Thermic efficiency, yet still retains 90% light transmission. In simple terms the polythene helps trap and preserve higher temperatures inside the structures for much longer - in heated structures, a 15-20% fuel savings can be achieved. A beneficial side effect of this added additive is that light entering the polytunnel is diffused - scattering light evenly throughout the structure. This UV stabilised film is 200 microns (800 Gauge) and is supplied with a five year guarantee.

FOR USE WITH All crops where heat is important such as bedding/annual plants, propagation houses & over wintered vegetable production.

Properties

Supplier

Our polythene is exclusively sourced from Sotrafa in Spain, the world's biggest producer of horticultural film with an enviable reputation for quality thanks to exhaustive testing in the demanding weather conditions of Almeria.

First Tunnels are the sole distributor of Sotrafa products in the UK, and we are proud to work with the global leader to deliver the best possible products for our customers. UK suppliers make cheaper alternatives, but the quality simply doesn't compare.

Warranty

Although guaranteed for 5 years against its biggest threat of sunlight degradation, when fitted correctly, it is not uncommon to hear our polythene covers have lasted in excess of 10 years.

5 Year Polythene Guarantee

View the terms of the Guarantee here.

Polythene Guarantee
UV Filters
Solar Radiation

Sunlight is the biggest enemy of polythene. While it's essential for the wellbeing of whatever you're growing, it also 'kills' polythene in much the same way you can find old discarded crisp packets lose their colour and become very brittle. First Tunnels polythene covers are developed and tested in the extreme conditions to give optimum performance and are UV stabilised to prevent the polythene from breaking down prematurely.

What is a KLy?

A Kilo-Langley is the measure of Solar energy radiated in 1 year. It varies from a minimum of 60 KLy in the Polar regions to 120 KLy in warm regions, and to a maximum of 200 KLy in the African desert. Southern Spain receives about 140 KLy whereas the UK receives about half of that, just 78KLy.

Thickness
Thickness

Our Super Therm polythene is 800 gauge/200 micron and made up of 3 layers for outstanding strength and performance.

We use a 3 layer polythene made of exceptional quality material, which has a hugely beneficial thermal effect.

The common misconception about polythene is the more layers, the better the product. Unfortunately this isn't true. More layers simply hide poor quality films, which are sandwiched inside a very average inner and outer skin. The result of these multi-layer (often called 5 or 6 layer) films is a noticeably poorer all-round performance - the thermal effect is significantly decreased.

Optical Properties
Total Transmission of Visible Light

Total Transmission of Visible Light
The amount of available light entering the polytunnel through the film. Measured as a percentage of total light.
Super Therm = 95%

Diffusion

Diffusion
The scattering of direct light entering the polytunnel ensuring no shadows, so all plants receive equal light. Measured as a percentage of total light.
Super Therm = 30%

Thermal Effect

Thermal Effect
A pocket of additives within the layers of the film that ensure and maintain a stable and optimum temperature within the polytunnel, especially during the night when it is colder.
Super Therm = 85%

Mechanical Properties
Strength at Break

Strength at Break
The load on a tested sample when it breaks. This is expressed in Pascals or MPa.
Super Therm = MD24/TD23

Elongation at Break

Elongation at Break
The strain on a tested sample when it stretches. This is also expressed in Pascals or MPa.
Super Therm = MD920/TD920

Creep

Creep
As the weather changes becoming hotter or colder, so the Polythene expands and contracts. Creep is the terms used to express this.
Super Therm = 5

Dart Test

Dart Test
A test to measure the impact strength on a test piece of plastic, using a weighted falling 'dart'.
Super Therm = 450

Smart Clear

This high quality Polytunnel film has been designed specifically for the UK where low light levels are common. This film allows 90% light transmission allowing through more of the light spectrum used by plants. It also scatters light entering the polytunnel. This UV stabilised film is 200 microns (800 Gauge) and is supplied with a five year guarantee.

FOR USE WITH All crops which are frost hardy, where you don't need to introduce heat, such as over wintered nursery stock, hardy herbaceous perennials, or where the poly tunnel is only to be used for summer production of vegetables or flower crops.

Properties

Supplier

Our polythene is exclusively sourced from Sotrafa in Spain, the world's biggest producer of horticultural film with an enviable reputation for quality thanks to exhaustive testing in the demanding weather conditions of Almeria.

First Tunnels are the sole distributor of Sotrafa products in the UK, and we are proud to work with the global leader to deliver the best possible products for our customers. UK suppliers make cheaper alternatives, but the quality simply doesn't compare.

Warranty

Although guaranteed for 5 years against its biggest threat of sunlight degradation, when fitted correctly, it is not uncommon to hear our polythene covers have lasted in excess of 10 years.

5 Year Polythene Guarantee

View the terms of the Guarantee here.

Polythene Guarantee
UV Filters
Solar Radiation

Sunlight is the biggest enemy of polythene. While it's essential for the wellbeing of whatever you're growing, it also 'kills' polythene in much the same way you can find old discarded crisp packets lose their colour and become very brittle. First Tunnels polythene covers are developed and tested in the extreme conditions to give optimum performance and are UV stabilised to prevent the polythene from breaking down prematurely.

What is a KLy?

A Kilo-Langley is the measure of Solar energy radiated in 1 year. It varies from a minimum of 60 KLy in the Polar regions to 120 KLy in warm regions, and to a maximum of 200 KLy in the African desert. Southern Spain receives about 140 KLy whereas the UK receives about half of that, just 78KLy.

Thickness
Thickness

Our Smart Clear polythene is 800 gauge/200 micron and made up of 3 layers for outstanding strength and performance.

We use a 3 layer polythene made of exceptional quality material, which has a hugely beneficial thermal effect.

The common misconception about polythene is the more layers, the better the product. Unfortunately this isn't true. More layers simply hide poor quality films, which are sandwiched inside a very average inner and outer skin. The result of these multi-layer (often called 5 or 6 layer) films is a noticeably poorer all-round performance - the thermal effect is significantly decreased.

Optical Properties
Total Transmission of Visible Light

Total Transmission of Visible Light
The amount of available light entering the polytunnel through the film. Measured as a percentage of total light.
Smart Clear = 95%

Diffusion

Diffusion
The scattering of direct light entering the polytunnel ensuring no shadows, so all plants receive equal light. Measured as a percentage of total light.
Smart Clear = 30%

Thermal Effect

Thermal Effect
A pocket of additives within the layers of the film that ensure and maintain a stable and optimum temperature within the polytunnel, especially during the night when it is colder.
Smart Clear = N/A

Mechanical Properties
Strength at Break

Strength at Break
The load on a tested sample when it breaks. This is expressed in Pascals or MPa.
Smart Clear = MD24/TD23

Elongation at Break

Elongation at Break
The strain on a tested sample when it stretches. This is also expressed in Pascals or MPa.
Smart Clear = MD660/TD820

Creep

Creep
As the weather changes becoming hotter or colder, so the Polythene expands and contracts. Creep is the terms used to express this.
Smart Clear = 5

Dart Test

Dart Test
A test to measure the impact strength on a test piece of plastic, using a weighted falling 'dart'.
Smart Clear = 450

Smart White

This specialist film reduces light transmission to 65%, and ultimately the temperature inside the structure. This film is most useful where sun scorch is a problem for growers. It is also suitable for animal husbandry applications and other stock and storage houses where a great build up of heat is not ideal. This UV stabilised film is 180 microns (720 Gauge) and is supplied with a five year guarantee.

FOR USE WITH Animal Husbandry structures and those plants that would normally grow under a shade canopy.

Properties

Supplier

bpi.visqueen is a division of British Polythene Industries plc - one of Europe's leading manufacturers of polythene film products. Their products are used by Farmers, vegetable, fruit and flower growers across the globe and are all designed to help the grower create their own 'climate for success'.

Warranty

Although guaranteed for 5 years against its biggest threat of sunlight degradation, when fitted correctly, it is not uncommon to hear our polythene covers have lasted in excess of 10 years.

5 Year Polythene Guarantee

View the terms of the Guarantee here.

Polythene Guarantee
UV Filters
Solar Radiation

Sunlight is the biggest enemy of polythene. While it's essential for the wellbeing of whatever you're growing, it also 'kills' polythene in much the same way you can find old discarded crisp packets lose their colour and become very brittle. First Tunnels polythene covers are developed and tested in the extreme conditions to give optimum performance and are UV stabilised to prevent the polythene from breaking down prematurely.

What is a KLy?

A Kilo-Langley is the measure of Solar energy radiated in 1 year. It varies from a minimum of 60 KLy in the Polar regions to 120 KLy in warm regions, and to a maximum of 200 KLy in the African desert. Southern Spain receives about 140 KLy whereas the UK receives about half of that, just 78KLy.

Thickness
Thickness

Our Smart White polythene is 720 gauge/180 micron and made up of 3 layers for outstanding strength and performance.

Optical Properties
Total Transmission of Visible Light

Total Transmission of Visible Light
The amount of available light entering the polytunnel through the film. Measured as a percentage of total light.
Smart White = 65%

Diffusion

Diffusion
The scattering of direct light entering the polytunnel ensuring no shadows, so all plants receive equal light. Measured as a percentage of total light.
Smart White = N/A

Thermal Effect

Thermal Effect
A pocket of additives within the layers of the film that ensure and maintain a stable and optimum temperature within the polytunnel, especially during the night when it is colder.
Smart White = N/A

Mechanical Properties
Strength at Break

Strength at Break
The load on a tested sample when it breaks. This is expressed in Pascals or MPa.
Smart White = MD23/TD22

Elongation at Break

Elongation at Break
The strain on a tested sample when it stretches. This is also expressed in Pascals or MPa.
Smart White = MD630/TD770

Creep

Creep
As the weather changes becoming hotter or colder, so the Polythene expands and contracts. Creep is the terms used to express this.
Smart White = 5

Dart Test

Dart Test
A test to measure the impact strength on a test piece of plastic, using a weighted falling 'dart'.
Smart White = 700

Net

This green net incorporates durable flat tape threads and double lockstitch tearproof technology and is used as a windbreak or shade product to protect those hardier and specialists plants. This net has proven its durability in the toughest of conditions and also provides excellent protection against insect and birds. 50% density.

Properties

Supplier

Tildenet is now considered to be one of the major brands of netting and textile manufacturers in the world. Exporting to over 100 countries, providing an extensive range of products for markets such as construction, sport and horticulture. Tildernet supply and manufacture extruded nets and meshes for all kinds of applications.

Warranty

Although guaranteed for 5 years against its biggest threat of sunlight degradation, when fitted correctly, it is not uncommon to hear our net covers have lasted in excess of 10 years.

5 Year Polythene Guarantee

View the terms of the Guarantee here.

Polythene Guarantee

Hoop Type

Help Me Choose

Unique to First Tunnels... We offer the option of the hoops of your Polytunnel to be supplied in a two or four piece design - Read the 'Pros and Cons' of each type, below...

Delivery

Four piece hoops have smaller sections making delivery easier and cheaper whereas two piece hoops have larger sections that require bigger, more expensive transportation.

Tell Me More

When ordering your polytunnel, time and consideration should be given to thinking about precisely where the delivery will be made. A 12ft x 25ft polytunnel would typically consist of about 10 items and weigh 160kg in total. The largest items of your delivery will be the hoops.

A delivery to your home might sound convenient, but please consider how you will transport the parts to site. Our four piece hoops will fit into the avarage family saloon, the two piece hoops will require a van. Obviously, the bigger the polytunnel, the larger the hoop sections.


Strength

Four piece hoops are the modern and customer focused approach with added hoop joint strengtheners. Just as strong if not stronger than the traditional two piece hoop. However the two piece hoop, doesn't require hoop joint strengtheners and is the favoured design for many suppliers, it is a lower cost to produce and quicker and easier to manufacture.

Tell Me More

A 2 piece or a 4 piece hoop?

Without getting too techy...A two piece hoop has one joint in the centre. Granted the number of joints in a four piece hoop is three but by spanning the two outer joints with heavy duty, steel joint straighteners this undoubtedly makes a four piece hoop as strong, if not stronger as the conventional two piece design. These Hoop strengthening joints are included as part of every complete Polytunnel kit, they are not required to be ordered extra like some competitors who also provide four piece hoops.

See these strength joints in action. View our 4 piece hoop withstanding an Atlantic storm with 60mph+ winds.


Time

When constructing, joining four pieces takes a tiny bit longer than joining two pieces.

Tell Me More

It's true... constructing a four piece hoop does take longer, perhaps 1-2 minutes per hoop for the average person. And like anything the more you do the quicker you become. So choosing two piece hoops might shave about 10 minutes off the complete build time of a typical 12ft x 25ft polytunnel and 10 minutes is less time than you'll spend making a brew.


Design

Four piece hoops are a quality solution engineered, tested and produced with the customer in mind. Two piece hoops are a solution for an easier manufacturing process.

Tell Me More

Why do we do a four piece hoop? - It's not cheaper, neither is it more profitable for us.

So Why...Authentic reviews from actual customers are an important resource for improving and addressing the needs and wants of our customers...We listened, you suggested a four piece hoop (for many reasons), we made it happen, and now you simply decide which you prefer..two piece, or four.

It's not AS easy to supply a four piece hoop - we have to roll the four profiles, swage each end (to slot back together) and then supply additional fixings and storm strengthening joint, not to mention the Q clips (all included at no extra charge). A two piece hoop is easier from a manufacturing point of view, but we aren't here for ourselves we are here for you.

We must be doing something right...check out our customer reviews.

Polytunnel Foundation

Help Me Choose

We have five options available. Foundation Tubes can be driven into the ground (if the polythene is to be trenched) alternatively you can use Anchor Plates. The Screw Anchor can be used if ground conditions are suitable. If you have a solid base of concrete or timber then Base Plates will be required.

More Info

Cover Fixing

Help Me Choose

We have three options available. The Trench method requires a trench digging all around the perimeter of the tunnel approx. 30cm wide and no less than 40cm deep. Quicker and easier than trenching the cover, are Base Rails, which are available in Timber or Aluminium versions.

More Info

Belts & Braces

Help Me Choose

We have three options are available. The Super Upgrade option allows you to upgrade the polytunnel hoops to 35mm – ideal for those very exposed and windy sites. Crop Bars are attached to every hoop apart from the first and last. Twin Support Brace runs down the full length of the tunnel, either side of the central ridge, both are ideal for hanging baskets, suspending canes/nets & crops.

More Info

Ventilation

Left

Right

Help Me Choose

We have three options available. Side Ventilation is a fixed rail (Timber or Aluminium) underneath which, is fixed a net windbreak, allowing ventilation and air flow. In addition we also have Timber Side Ventilation & Screen, which allows the net to be covered through the use of a screen, which can be lowered/raised, helping control temperature and air flow. Please note, the Screen is not compatible with Aluminium. All options available, for one or both sides.

More Info

Useful Extras

Help Me Choose

Ground Cover inhibits the growth of annoying weeds. Acting as an excellent sub-base for use with bark, mulch or gravel. Ground Cover provides total floor coverage, supplied with metal staples.

Staging introduces a work surface at the ideal height of 75cm, significantly adding growing space. Complete with brackets, allowing you to attach a worktop (not supplied) of your choice. 

Polythene Care Kit contains 1 roll of 4 inch repair tape and a 2.5 litre container of Algon Organic.

Useful Extras
More Info

Irrigation

Help Me Choose

Overhead Irrigation comprises a water pipe suspended below the central ridge. Supplied with a header pipe, down tubes, sprinklers, inline tap, pressure regulator and hose connector. This complete kit is ready to go, just connect a hose and you’ll be amazed how quickly it will pay for itself in terms of time, money and improved productivity.

Automatic Overhead Irrigation is supplied with the added advantage of a weather resistant, battery operated hose end water timer. Essential for those days when you just can’t be there to operate the system manually.

Irrigation
More Info

Polytunnel Door Options

Front

Rear

I want to design and build my own doors

Help Me Choose

All Polytunnels supplied come complete with two doors. We have hinged and sliding door options...

Hinged Doors

The top panel is covered in Shade Net to allow ventilation whilst the lower half is covered with polythene to prevent low level draughts.

The Outer Door Frame is 75mm x 47mm, whereas the Inner Door is 50mm x 50mm. All timber used is FSC® certified.

Door Options
No Door Option

We also offer a DIY option...make your own doors. If you prefer to build your own bespoke doors  - you can exclude the doors and timber end frames and receive a discount.

Sliding Doors

All door panels are covered with polythene, ventilation is easily controlled as you can slide the doors open to leave any gap of your choice. Sliding doors sit securely on the doorframe, flush to the polytunnel, and out of harm's way.

The Outer Door Frame is 75mm x 47mm, whereas the Inner Door is 50mm x 50mm. All timber used is FSC® certified.

Door Options
No Door Option

We also offer a DIY option...make your own doors. If you prefer to build your own bespoke doors  - you can exclude the doors and timber end frames and receive a discount.

Freebies

Help Me Choose

When you buy one of our Polytunnels you will receive a Free Polytunnel Lucky Bag, consisting of the following:

The two best selling Polytunnel books by Andy McKee and Mark Gatter.

Crop wheel, a wealth of growing information...when to sow, grow, harvest and a really useful measuring device too.

Polytunnel planner, the essential monthly planner packed full of tips and advice.

Tomato seeds, specially selected to help you get your polytunnel growing...they taste yummy too.

Polytunnel Growing Guide, will take you through a whole 12 months of activity in your polytunnel.

Free Gifts