Snow On My Greenhouse

Elite GX800 in the snow

Hi all just a quick reminder in this cold weather. You might not be in mood for entering into the garden, however if you’re the proud owner of a greenhouse i would recommend it, Why? you might ask.

Well certainly for those in the east who are encountering the most snow fall at present they will find that a certain amount is building up on the roof of your greenhouse. At first glance it may seem harmless; however it might be worth noting that potentially it could do more damage than you might think.
For example, the weight of freshly fallen snow is approximately 100 – 150 kg / cubic meters. And once it has fallen on a solid surface the effect of compaction due to its own weight the wind and other additional factors rapidly increases the weight of the snow.

View from the inside of a snow covered glasshouse

To put it in context if the roof of your greenhouse had a surface area of 16m squared, and we received 50mm of snow which is about two inches, you would have .9 of a cubic meter of snow on your roof. This equates to approximately 80 – 100kgs. If this snow freezes the weight on the roof increases. Depending on the model of greenhouse that you own, it’s worth noting this may affect the structure of the greenhouse.

To avoid any damage or the possibility of a complete collapse of the greenhouse I would recommend that you clear it of snow as it builds up. Please note that this is perfect excuse for going out to throw snow balls, so thankfully it’s not all bad news.

Happy gardening.

Polytunnels & Frost Protection.

Our 4.5m wide model left out in the cold.

Polytunnels like other greenhouses provides protection for crops over the colder winter months. The biggest threat to plants during this colder period is frost.

Frost causes the water in plant cells to freeze. The result of this is damage to the cell wall which leads to wilted growth causing the plant to become blackened and distorted.

Under sever frost the temperature will drop to a point where only supplementary heating inside the tunnel will protect against the cold.

But before reaching this point, there are some steps that maximise your tunnels ability to protect against the frost.

Make sure your tunnel is located in the sunniest location of the garden. This allows your tunnel to heat up during the day in the low winter sun.

Clean your tunnel cover annually. This will reduced any obstructions to the sunlight passing through the polythene which will also help heat the tunnel.

Finally make sure when purchasing your tunnel than you only use a thermic plastic, which has good thermal properties. This will help reduce heat loss through the cover thus giving better protection to your crops during winter.

Thankfully its nicer inside than outside the tunnel.

Community Gardens

Recently I saw an article in the Sunday Times written by Gabrielle Monaghan. It was great to read something more positive than the normal doom and gloom that is seen in our daily media reports thanks to our current economic crisis.

Gabrielle wrote about the Mount street club Trust. It origins and how it contributes to building and improving our community.

The Mount Street Club was established in Dublin in 1934. Its aim at the time was to give the unemployed the chance to work in return for food. As our state improved and social services increased unfortunately the mount street club services became more and more redundant.

However more recently the mount street trust has put forward new incentives to help tackle current difficulties in our communities. It now hopes to offer the employed an opportunity to get involved in growing their own again. They hope to do this through allotments and community gardens as part of €330,000 project.

The mount street club trust is using money from the 2006 sale of its former headquarters to fund the project. They are offering up to €10,000 in grants. Community gardens have been invited to apply if they involve the unemployed in the planting, growing and harvesting of food.

As part of the new scheme, gardening experts from Grow it Yourself (GIY) a charity established last year will provide groups with access to unused land or local authority plots. The fund is being distributed be the community foundation for Ireland.

Corrigan Cooks Naturally


Grow your own has enjoyed a new lease of life over the past few years. Now more than ever people are turning back to their gardens, small holdings and whatever free space they can find to try their hand at growing their own.

For those who are looking for some inspiration to get them started then I strongly suggest having a look at a television series currently running on RTE 1. It is hosted by celebrity chef Richard Corrigan and it’s called Corrigan Cooks Naturally. His mottos are Taste Local and celebrate what’s local, what’s good and ultimately what’s natural.

This year he has his own Corrigan Cooks Naturally Roadshow and he’s bringing it all around the country. He has recruited a few experts to give him a hand. Vivienne Campbell medical herbalist who can show you how plants and flowers can make remedies and even natural beauty products. Along with her is horticulturalist Kitty Scully who wants us all to reconnect with our food heritage.

I have to give it to them; it’s a great show and gets the mind going. As well as the fantastic ideas that can be gotten from the show you will also find great recipes that gets the taste buds tingling. So it one to watch. It’s on Wednesdays 20.30 – 21.00.

Polytunnels at Ploughing 2010

Hello everybody,

Recently our time for blogging has been limited. There was huge interest in our stand at the ploughing championships. It’s only now we are finally getting through these enquiries and therefore getting back to our day to day duties.

I would like to thank everyone that came to visit our stand during the ploughing championships. Over the coming weeks we hope to contact you all. And look forward to talking with you and answering any questions that you may have as a result of seeing our stand.

As always you can find lots of answers to questions already on your mind at www.polydome.ie and please feel free to contact us directly at our office.

Talk soon everybody….

Polythene Covers

Today I spoke with a customer. They had been a little confused about Polythene covers. They had seen both a 720 gauge and 800 gauge polythene sheets. At a glance both look identical. Which prompted the question, what are the differences?

There is a lot of options with polythene sheets which can cause confusion. However we recommend for most customers growing a variety of vegetables (or bedding plants and flowers) 800 gauge (200 micron) clear polythene. Most 800 gauge polythene covers give high light transmission which is most important in this country. It also is important that the polythene is ‘thermic’ meaning it is good at reducing heat loss on cold nights. You should always check with your supplier that there polythene has these features. While most of our customers grow organically we need to point out to those who use chemicals that their use around the polytunnels can affect the life of the cover.

At Polydome we give our film a 6 season warranty against UV degradation although it can last longer depending on the amount of sunlight it receives during its lifetime and the laying conditions during installation. A cover tensioning system in our Polydomes Tunnels helps to prolong the cover’s life. Being 800 gauge it is tougher than lighter films which helps protect it in storms and gives longer life than lighter films.

Siting your Greenhouse

A sunny position is most important for plants to grow well. For strength you must point the gable end towards the prevailing wind. If there is a slight slope on the site you should run the length of the Polydome down the slope (apart from structural reasons this will help ventilation). You need to allow room all around the Polydome for digging trenches and avoiding snagging the cover on things, if we are constructing we ask for about 1.5m on either side of the Polydome and 2m at either end if possible. You should have some shelter from prevailing winds using trees or windbreak net which will filter the wind. You should avoid choosing a stony, boggy or very sloping site if possible as it requires extra materials and work to build.

Polydome Blog

Hello All,

Welcome to Polydome’s new blog. We are delighted to be finally online.

Over the coming months we hope to use this source as a means to sharing with you our experience in the greenhouse industry. Over the past 25 years Polydome has become one of the largest suppliers of hobby polytunnels and glasshouses within Ireland. We now hope to pass on some of the knowledge and expertise we have gained over the years. We hope this information will help anyone making the next step in purchasing or making their own greenhouse.

So watch this space.

Irrigation In Polytunnels

The majority of vegetables are 80 to 95 percent water. So next time you look at your lovely vegetables in your tunnel or glasshouse think of them as little sacks of water, flavoured and full of vitamins.

But remember, if the supply of water fails your vegetables yield and quality will suffer rapidly. In the high temperatures found in polytunnels and glasshouses it’s very important to irrigate on a regular basis and guarantee a reliable supply.

The two most common methods of irrigation are overhead irrigation and ground level irrigation. Overhead is by far the simplest method. Water is released from sprinklers suspended from the roof of the tunnel or the glasshouse. These form a mist which saturates everything in the tunnel.

Some draw backs of overhead irrigation: water is wasted as it not only falls on the beds and plants, but also the walkways through your greenhouse as well as work areas: sun spots are more likely to occur as the result of droplets forming on the foliage: and a large number of plants prefer being watered into the root as appose to directly onto the plant itself.

Ground irrigation is a much more effective method. Lines of perforated pipe lay on top of the vegetables beds. Built in regulators in the perforated pipe leak out a set amount of water per hour. This allows even irrigation across the bed and more importantly directly into the root.

However it does have its drawbacks also. More pipes + more fitting = higher costs. Also, as the pipes sit on top of the beds they sometimes can be in the way during weeding and planting.

Don’t forget to automate your irrigation system if you’re away for long periods, therefore guaranteeing that your plants get their daily dose. Tap timers are a simple and effective solution. These can be gotten in many garden centres and DIY shops and are very easy to install.

If you require further information feel free to visit our website.

The picture on the left is of an overhead spray line. The picture on the right is drip irrigation.

The Urban Garden

Over recent years “grow your own” received a new lease of life, and many have the idea of growing their own fruit and veg. For people living in the countryside the space needed to do this has not been an issue. But for those in the urban environment lack of space can pose many problems. Nevertheless this shouldn’t be a limiting factor.

You can choose different varieties of fruit and veg that are bred to grow in small spaces. If they have the words patio, pixie, tiny, baby or dwarf in their name it is a good bet. Remember plants that are bred to be small doesn’t mean the fruits will be small or the yield less. Normally by looking on the seedling pack it will tell you the mature size of the plants you are selecting. You can then decide which suits your space best.

Vegetables need a good 6 or more hours of sun each day. Without sun, the fruits will not ripen and the plants will be stressed. Some crops that can survive in light shade are lettuce, broccoli and other cole crops. For those who have shaded balconies or north facing apartments it’s important to give good consideration to crop selection as lack of sunlight could be an issue.

For those who always wanted their own greenhouse but thought they didn’t have the room you will be glad to know must manufacturers cater for this end of the market. And as they are small, they are also very affordable. Some examples are the Eden/Halls lean-to (2 ft x 4 ft model). and the Elite window garden.  

So maximize your limited space, carefully select your crop and enjoy the pleasures of happy growing……