Coldframe Construction – Building One Yourself, DIY

coldframe construction
Finished Product

Coldframe Construction

This weekend in the midst of hurricane Desmond battering Belfast, I took to the blogs and to twitter to connect with some other allotment folk and to introduce our blog to them. Chris on the other hand got stuck in and built our very first Coldframe construction.

The wood primarily came from pallets and floorboards which had been salvaged. We are very keen to recycle as much materials as possible. The door with the glass was pulled of a skip (with the owners permission) last summer with the intention of constructing a coldframe. The only part of the structure that we had to pay for were the hinges, even the screws were free as Chris won them on a scratch card after making a purchase at Tradepoint at B & Q.

Last year Chris’s kitchen and living room windows were covered from top to bottom in sprouting seeds he had begun to grow indoors. However when it came time to plant them out, we got hit with a cold snap and months of work had been ruined overnight. it was then we agreed that making a Coldframe construction to keep our seedlings safe in the process of hardening them off for outdoor planting, was a good idea.

 

coldframe construction
Materials Used

 

coldframe construction
Coldframe Construction

Our process for hardening off seedlings will follow something like this to ensure we gradually introduce them to the elements

  1. Place seedlings into the coldframe construction to protect them from strong sunlight, potential frosty nights and less-frequent watering. This will take approximately 1 week
  2. As the temperatures start to rise, we’ll open the cold frame roof for a small time of approx 2-3 hours of sun. Another 2-3 days.
  3. Increasing the time the seedlings are exposed to the elements but closing the lid as and when more serious weather systems come into play – 1 more week

Transplanting the seedlings into the ground when they have successfully hardened off will give us the best chance of growing from seed, something Chris and I are very happy about as the cost savings will be huge.

coldframe construction
Coldframe

Choosing a Polytunnel – A helpful guide

 

 

 

 

polytunnel

 

So the boys here at growblogs are in the market for a polytunnel. This was a decision we made long ago but decided to hold off until the start of the next growing season to save our new purchase a harsh winter. There are many advantages to growing in a polytunnel compared to just growing in the open ground.

Growing Season – One of the main advantages of owning a polytunnel, and one that for us in particular due to our location in Northern Ireland, is the fact that you can greatly increase your growing season. It is possible to start the season from 2 – 6 weeks early, and extend it by roughly the same, dependant on location. We reckon that here in Belfast, that could give us a good 7 – 8 weeks extra growing time which will greatly increase our yield.

Temperature – The temperature inside a functioning polytunnel will be significantly greater than outside, and will vary easily. It is possible to continue growing all through the winter by introducing heat into the tunnel in various ways.

Variety – There are certain types of fruit and vegetables that are only able to be grown in greenhouses or polytunnel. Certain heat and light loving varietys would just not be possibly for me to grow without the finest of summers. Tomatoes, Cucumbers, Chillies and Courgettes all need good conditions to grow well and they just would not be an option for us to grow out doors.

Protection from weather – Polytunnels have their own micro climate and if well sealed and airtight, will keep the contents well protected from the elements.

Protection from pests – The protective film creates a barrier to the insects from your crops. However they will try everything possible to get inside and if they do find a way in, finding their way out will seem fruitless and difficult.

The only real disadvantage they we have discovered so far, is that you cant leave it up to mother nature to water your covered crops. There are ways around this with many automatic watering systems on the market and many more ingenious methods amateur gardeners have been perfecting for years.

Off to the shops.

One of the best friends to modern man is online shopping. The ability to browse countless products and have them delivered to your home all from the comfort of your pyjamas. At first when I googled “Polytunnel UK” I was slightly overwhelmed by the amount of online shops, sell many types and sizes and the greatly varying prices between some of the products. It was then that I reliased that I was gonna have to do some some research to get the most bloom for my buck.
Having spent a few hours going through all the websites and everything I could find on the subject online I came to the conclusiuon that a) there is actually very few differing products, ans b) the difference between quality and price differs greatly.

The cheaper polytunnels come with a green mesh cover as compared the the much dearer clear filmed covers.

The online sites that sell these products explain in detail the science behind the different tunnel coverings and give advice on which would be the best for your own needs.

 

polytunnel

One of the reasons why I believe there is a lack a of a good mid range polytunnel is the commitment that it takes to make the most of the tunnel. Gardening for many people can be a fly by hobby, falling into the same category as golf, fishing and many other activities of whose accessories litter roofspaces and garages throughout the country. When speaking to our fellow allotmenteers there has been countless stories of people being offered a new plot and they go at it all guns blazing for a few months, then as soon as the weather changes or the novelty has warn off, they are never to be seen again. When you receive a new plot it can very much feel like your playing catch up with your neighbours. It can be disheartening looking at a bare plot when all around you are neatly spaced rows of lettuces and gleaming greenhouses. Often the temptation could be to throw some money at the problem and purchase a cheap polytunnel to cover that bare ground and get the growing process underway. These hobbiests are unlikely to spend upwards of £800 on a polytunnel unless they are determined they are in it for the long haul.

While the smart money says “its an investment, “it will pay for itself” the best part of £1000 is a lot of money. If I knew the polytunnel was going in my garden or field where I lived it would be a lot easier parting with the money. Ive been warned about leaving valuable tools in our shed, due to thefts, that im sure occur on allotment sites all over the country. Also random acts of vandalism, that do happen, it only takes a small knife to do a lot of damage to a polythene structure, and we all know there are lots of people out there they who enjoy nothing more than spoiling other peoples fun.

Mother nature can also be a polytunnels enemy. Wind would be a particular issue. While every attempt will be made to firmly secure the tunnel accidents do happen and a particularly strong gust of wind could literally see your investment take off.

Taking all of this into consideration and at our next monthly Growblogs Directors meeting (down the pub) we will be weighing up the options do we go a) cheap and cheerful, b) costly and concerned or c) do we try and build our own like the shed which turned out, cheap and cheerful at first then turned costly and caused much concern.

Chris