How do I choose from this lot? The Editor's opinion.

Hi. Thanks for taking the time to see what we think.

Buying a greenhouse can be a pretty frustrating affair... and it's probably something you'll only do once or twice in a lifetime.

Getting unbiased advice is almost impossible as everyone has a different opinion (and I'm no exception to that).

I've tried to summarise below what I have been telling customers for over 20 years when I have met them face to face at our display centres. While I don't claim to be the world's leading expert, we (GBC Group) have sold many millions of pounds worth of greenhouses and have consequently built up a wealth of experience.

Click here to go to specific details about the 6ft wide greenhouses
Click here to go to specific details about the 8ft wide greenhouses

First a brief explanation of what’s on offer at large in the greenhouse market:

Specialist greenhouse retailers - There aren't many of us around! GBC have displays of twenty or so greenhouses in different shapes and sizes at each of our 23 branches. We have timber greenhouses and aluminium greenhouses, Freestanding or Lean-to Greenhouses, Octagonal or Dwarf Wall greenhouses. We have staff on hand to explain the features and benefits of each greenhouse and discuss the relative merits of various types of staging, glass, ventilation and so on. We believe that you should see what you are buying and understand about how it is sited and installed.

Internet greenhouse retailers - There are a couple of companies who offer greenhouses exclusively on-line who, at first glance, are offering cheaper prices than the specialist stores. In general you will not be able to see before you buy which, given that a greenhouse is a once in a lifetime purchase, you would be well advised to do.

DIY and Chain stores - Visit some of the big DIY chains and you will generally find a small number of greenhouses which have been selected to be as cheap as possible. In order to achieve this you will find that the framework is not very substantial, there will only be one roof ventilator (which is nowhere near enough), and glazing may be with double wall polycarbonate (which is bad news). You can tell I'm not impressed but, if you simply want the cheapest greenhouse possible, stop reading now and take yourself to your local DIY store.

So on to the decision making process:

What size of greenhouse do I need?

This is the billion euro question to which I offer three subjects to consider:

How big a greenhouse can you sensibly fit in your garden?
Whatever you choose to grow in your greenhouse it will never be big enough! The reason for this is that you will fill up the staging with seed trays in spring, each of which will yield you anything from ten to a hundred plants which you will then pot up individually ( If you are like me you'll be so pleased that they have grown that you won't want to chuck them out). The inevitable result is that you don't have enough space! So choose a greenhouse that will accommodate enough potted-on seedlings to satisfy you!
The vast majority of people want to grow some tomatoes or over-winter fuchsias or geraniums as well as start seedlings in their greenhouse. Normally one growbag with three tomato plants in it will be enough to keep the average family going through the summer... so the greenhouse doesn't need to be very big to accommodate that. Over-wintering requires staging and shelving so this takes up space that you will need to start seedlings off in in the spring... so consider this too.
Don't forget that bigger greenhouses cost more to keep warm in the winter if your prime reason for buying is for over-wintering.
What can you afford?
Price simply has to be a consideration and the bigger the greenhouse the higher the price. I'd rather have a smaller greenhouse with adequate ventilation, safety glass, and working surfaces than a big greenhouse that doesn't have those features. Ultimately, you have got to want to use the greenhouse once you have bought it and if it isn't a pleasure, you'll probably not use it.
What will it look like?
Unless you are completely thick skinned you will want to consider the impact the greenhouse has on your garden and your neighbours too. A huge greenhouse sited on the boundary may not be the best idea! We sell an enourmous number of greenhouses with coloured frames and ridge cresting. These don't help the plants to grow in the slightest but they do make the greenhouse a feature in your garden. I guess I'm back to what I just said... you want to enjoy using it so if it is in a prominent location, try to make it a pleasure to look at as well as to use.

Timber Greenhouses or Aluminium Greenhouses?

You may not have considered this yet as it is generally the greenhouse specialists like GBC who provide timber greenhouses.

Timber (by which I mean pressure treated pine or Cedarwood) greenhouse manufacturers claim their greenhouses are warmer in the winter... although I used to be sceptical about this I have to admit that, in the winter, if you walk into a timber greenhouse and then into an aluminium one the difference is noticeable. This seems to be because the timber doesn't transmit cold the way that aluminium does. In theory timber greenhouses are therefore cheaper to keep warm. They are certainly easier to fit with insulating bubble wrap in the winter … you just staple it on!
Timber greenhouses look good in the garden... Cedar is a natural product and blends in well with most garden schemes. There's a myth that says that cedar greenhouses don't need maintenance. Cedar has its own natural oils and protects itself against rot so there is some truth in that, but a cedar greenhouse will look tatty in a couple of years if you don’t put a coat of preservative on it periodically. I would recommend treating it annually with a coat of a decent spirit based preservative which will penetrate the timber and protect it. If you forget to do it one year, no matter, the cedar won't rot so do it the following summer!
Aluminium greenhouses are maintenance free. This is largely true, they just need a good wash once in a while. Plain aluminium frames won't stay shiny, they will eventually oxidise to some extent and leave a whitish surface coating. That is best left alone as it does no harm and stops further weathering.
Painted aluminium frames are also maintenance free... providing the powder coated paint was put on properly to start with. We have seen the result of cheap paintwork and it isn't pretty. Fortunately, in over 20 years, our suppliers have never taken short cuts with their powder coatings and we don't have people lining up to have their greenhouses replaced!
Aluminium Greenhouses are cheap. They are cheap relative to timber greenhouses but, as I said, this is a one-off purchase so are you buying cheap or are you buying what you want? When considering coloured frames for aluminium greenhouses, you'll find that timber isn't so expensive after all!

Where should I site the greenhouse in the garden?

Unless you are a complete anorak there's a simple answer to this - Put it where it is convenient and then you will make use of it.

If you want to get technical then various books will tell you to align the ridge with various points of the compass. My advice in that case is to simplify matters by saying:

Don't have the door at the North end (it's colder)
Don't run your staging along the south wall (your plants might fry)
And don't put it directly under a tree!

Above all we want you to enjoy using your greenhouse so don't make it inaccessible... you'll also find that the nearer it is to the house, the easier it is to run electricity out to it which leads me on to:

What sort of heating should I use ?

I have tried the following: Paraffin; Calor Gas; Electricity.

Briefly, the first two involve a lot of faffing about. You need to be around constantly to adjust wicks, fill tanks, light up, switch on and off and so on. In today's health and safety conscious days it also means that you will have flammable materials lying about in your garden. Keeping a constant temperature is also difficult since, once the sun is out on a winter's day, there's often no need for heating at all and yet you will be busy burning fossil fuels!

So for me it is electricity every time. Use a thermostatically controlled electric heater which will come on to protect from frost damage but switch off as soon as the temperature rises naturally. You can turn it up once you start seedlings growing.

Please make sure your supply is professionally installed and RCD protected.

What type of glazing should I choose?

This is a very good question. There are three predominant types of glazing for domestic greenhouses.

Horticultural Glass - This is 3mm glass and has been in use for decades.
In aluminium greenhouses it is supplied in 2ft square panes so, where the panes overlap on the sides and the roof, there is the potential for green slime to grow between the panes … and it does. It takes a year or so to get going and is next to impossible to clean out.
If horticultural glass breaks it can be very dangerous and we wouldn't recommend it for use anywhere where small children or unsteady adults are likely to be. In fact, we wouldn't recommend it at all.
The only reason it is available is that it is much cheaper than the alternatives and some customers (particularly the older generation who have always used horticultural glass) see no reason to pay extra for safety glass. They also like the fact that breakages are cheap to replace; horticultural glass can be cut to size whereas toughened glass has to be cut before toughening and replacements of angled sizes can be costly.
However, it's highly unlikely that you will manage to break a pane of toughened glass in normal circumstances.
Toughened Safety Glass - This is my recommendation.
Properly kite-marked toughened glass will break into small pieces if you manage to break it. The panes generally fit in one piece into the greenhouse frames without overlaps which means less draughts and they are much easier to keep clean. The edges are very rarely sharp and it is easy to handle as a consequence. If you are putting up a greenhouse yourself this should be a major consideration... do you really want to be lifting panes of horticultural glass above your head height?
Toughened glass will normally take an impact from something like a football; to break it you would need something like a stone thrown up at high speed by a strimmer. If you have children, grandchildren or pets, then toughened glass has to be the glazing to choose.
I have to say that no glass is truly 'safe'. Even fragments of toughened glass can cut but it is streets ahead of horticultural glass.
For total safety you can choose polycarbonate glazing - but that has other drawbacks which I will outline below. I like the fact you can see through the glass to your crops, and to see whoever is inside. If you are inside the greenhouse you can see out to your garden too whereas with polycarbonate glazing you are cocooned inside with no view at all.
Polycarbonate Glazing
In theory, polycarbonate should be a great material to glaze greenhouses with. It is a popular choice on the continent but has never really got hold in the UK. Polycarbonate as used in greenhouses is a twin wall plastic with honeycomb sections which is fairly efficient thermally. It will retain heat inside a greenhouse in the winter better than glass because of the double glazing effect- So what have I got against it? What no one will tell you is that polycarbonate is NOT a sealed unit. Although sometimes the ends of the plastic are taped over when you buy polycarbonate, this tape won’t stay on. Therefore the hollows inside the polycarbonate can fill up with condensation and therefore they can go very green inside the material where you can't clean it. Insects can also get inside the hollows and they can’t be coaxed out either.
Polycarbonate used for greenhouses is inevitably very flimsy as it is kept as cheap as possible. It also needs to replace glass so it is made as thin as possible to stay in the same frames. So what happens to it in stormy weather? The answer is that it is much more likely to be blown out of the greenhouse than glass. Once one panel goes the whole greenhouse is at risk since the wind can then push the other panels out with relative ease.
If you choose polycarbonate then you must choose a greenhouse system which has proper 'bar capping' which secures the polycarbonate along its entire length. This isn't a cheap alternative... in fact a greenhouse properly glazed with polycarbonate is likely to cost a great deal more than with glass.
Don't forget that you can't see in or out of a polycarbonate glazed greenhouse.

6ft wide greenhouses available from GBC

You may have jumped straight to this summary of the differences between our different 6ft wide greenhouses. If so, there is various information above that you may also find helpful in making your choice. Click here to go back to 'What size of greenhouse do I need?'

Basic Aluminium (Painted or plain frames)
The Craftsman and the High Eave are good, sturdy greenhouses at the lower end of our price range. There's a huge range of optional extras and sizes range from 4ft x 6ft up to 20ft long. For item prices contact us on 0800 999 0123.

The Stirling Package and The Arundel package are greenhouse packages that we have created to incorporate the elements we would personally like to see in our own greenhouses: staging and shelving; additional and automatic ventilation; rainwater goods and toughened safety glass. These are our best selling greenhouses as a consequence. You can buy online or call us for more details.
Our recommended choice for a basic starter greenhouse

Premium Aluminium (Painted or plain frames)
GX600: This is a high specification, sturdy greenhouse available from specialist greenhouse suppliers such as GBC only. Plenty of ventilation is built in as standard and doorways have low thresholds which make this greenhouse the inexpensive choice for easy access.

The Solent package is a variation on the GX600. It adds to that greenhouse with staging, door lock, rainwater goods and barrel, automatic ventilation and more. The Solent is our recommended choice for a sturdily constructed greenhouse with all the features you would expect from more famous greenhouse brands. This is available to buy online.

Premier Aluminium (Painted or plain frames)
Robinsons Regent - Robinsons greenhouses are well known for their superb finish and sturdy construction. Low threshold access, door locks, and toughened safety glass as standard are some of the benefits you will get from buying Robinsons.
This is the best of our 6ft wide freestanding greenhouses. Recommended choice if you want to push the boat out!
You can buy the Regent with your own specified range of accessories or choose one of our immensely popular package deals which are available online.

Timber
Click here to find out more about timber greenhouses
Malvern Pressure treated greenhouses - Pressure treatment is literally that: all components of the greenhouse are placed in a large pressurised cylinder which forces the preservative deep into the timber. The formulation of the preservative gives the pressure treated greenhouses their green/yellow hue which complements so many gardens. Good looks, an extended lifetime and lower cost than cedar are the main benefits of choosing pressure treated construction.

Cedar Greenhouses from Alton and Malvern

Choose a Malvern Cedar Greenhouse and we'll generally install it for you too! Available with 'Dutch light' slant sides or in a roomier straight sided version, the Malvern Greenhouse range is exceptionally popular.

Alton are perhaps the best known brand in greenhouse gardening. We have customers coming in to replace Alton greenhouses they bought thirty years ago - not a bad lifespan for a garden building! All Alton buildings are constructed in cedar and have toughened safety glass as standard.

Ease of installation tips the balance in favour of the Malvern Greenhouses but Alton have a great reputation too so you’ll be more than happy whichever you choose!

8ft wide greenhouses available from GBC

Basic Aluminium (Painted or plain frames)
The Belmont is a good, sturdy greenhouse at the lower end of our price range. There's a huge range of optional extras and sizes range from 6ft x 8ft up to 20ft long. For item prices contact us on 0800 999 0123.

The Monmouth package is a package we have created to incorporate the elements we would personally like to see in our own greenhouses: staging and shelving; additional and automatic ventilation; rainwater goods and toughened safety glass. These are our best selling packages as a consequence. You can buy on line or call us for more details.
Our recommended choice for a basic starter greenhouse

Premium Aluminium (Painted or plain frames)
GX800: This is a high specification, sturdy greenhouse available from specialist greenhouse suppliers such as GBC only. Plenty of ventilation is built in as standard and doorways have low thresholds which make this greenhouse the inexpensive choice for easy access.

The Solway package is a variation on the GX800. It adds to that greenhouse with staging, door lock, rainwater goods and barrel, automatic ventilation and more. The Solway is our recommended choice for a sturdily constructed greenhouse with all the features you would expect from more famous greenhouse brands. This is available to buy online.

Premier Aluminium (Painted or plain frames)
Robinsons Royale greenhouses are well known for their superb finish and sturdy construction. Low threshold access, door locks, and toughened safety glass as standard are some of the benefits you will get from buying Robinsons. You can buy the Royale with your own specified range of accessories or choose one of our immensely popular package deals which are available on-line.
This is the best of our 8ft wide freestanding greenhouses. Recommended choice if you want to push the boat out!

Robinsons Riviera - This is a greenhouse with a difference; the difference being the roof shape and the facility to site the door on the length rather than the width. Two sizes are available and a full range of accessories can be specified.

Timber

Click here to find out more about timber greenhouses

Malvern Pressure treated greenhouses: pressure treatment is literally that: all components of the greenhouse are placed in a large pressurized cylinder which forces the preservative deep into the timber. The formulation of the preservative gives the pressure treated greenhouses their green/yellow hue which complements so many gardens. Good looks, an extended lifetime and lower cost than cedar are the main benefits of choosing pressure treated construction.

Cedar Greenhouses from Alton and Malvern
Choose a Malvern Cedar Greenhouse and we'll generally install it for you too! Available with 'Dutch light' slant sides or in a roomier straight sided version, the Malvern Greenhouse range is exceptionally popular. Please read about the benefits of choosing a timber greenhouse in the section above.

Ease of installation tips the balance in favour of the Malvern Greenhouses but Alton have a great reputation too so you'll be more than happy whichever you choose!