Greenhouses: glass versus polycarbonate. Is there much difference?

I wrote a blog post a good while back now asking if an unheated greenhouse really made much difference and I think having one here in the cold, wet north really was a great tester.

In that post, one of the things I commented on was the fact that I had no experience of the difference between a traditional glass greenhouse and a polycarbonate one, so couldn’t offer a more specific analysis.

Well we are at the end of our first spring season with the new glass greenhouse now, so I thought this would be a perfect time to give you an update and tell you if there is a difference or if you should save your pennies and stick to the cheaper options.

So let me answer the question straight off, which is better glass or polycarbonate?

Glass, absolutely no doubt. I don’t think I could switch back now.

There you go, blog’s over :P. Kidding…… let me tell you about my experience.

If you are a regular here you’ll already know the stories of my greenhouse and its travels, but bare with me as I let the newbies in on our adventures.

I have had a polycarbonate greenhouse for about 6 or 7 years now. It was a few hundred quid, so was affordable whereas at the time of buying it, I couldn’t really afford to shell out a grand on a glass greenhouse when this was my very first trek into gardening and I didn’t even know yet that I was going to be hooked.

And let me say this up front. I was VERY happy with my greenhouse. It really made a difference and I found seeds took faster and seedlings came on faster than anything I planted outdoors. It also offered protection from frosts and in summer when it was sunny, it doubled as a staycation resort.

However, the thing it didn’t cope with was wind and rain. Basically if it rained, the greenhouse leaked like mad. Water got into the corrugated roof panels and they filled with green, algae type stuff which meant cleaning every year was a massive job and less than pleasant.

When it was windy, my heart was in my mouth, regularly I would have to go on early morning treks around the neighbourhood looking for roof panels which had blown off in the wind and gone off on their own adventures and the greenhouse ended being held together with gaffer tape and hope.

Greenhouse wind damage

Things finally came to a head last year when I lost multiple panels, most of the clips that held the roof in place and the window was torn out by the wind and completely bent and also ripped the frame so it couldn’t be fitted back in again. We decided enough was enough and bought a glass greenhouse which advertises specifically that it is capable of coping with even the worst winds.

We got it installed in November though, so spent the winter with a beautiful shiny new greenhouse but nothing to grow in it.

Until now… I can finally give you an update on my experiences and compare.

Glass versus polycarbonate

So as I said, the polycarbonate greenhouse absolutely did its job when it came to growing stuff. Seeds germinated and seedlings grew and things definitely came on faster than outdoors.

However, this spring with the glass greenhouse, EVERYTHING grew. EVERY SINGLE SEED. Leaving me with a massive conundrum, because I always plant more than I need, because usually only about half came up. Basically, I gave away 20 tomato plants and a similar amount of peppers and chillies this year, as we had so many healthy, strong plants. Not only that, but once things had started, they came on at an alarming rate (well alarming for me).

The other big difference I notice is that the glass greenhouse is so well put together, there are no gaps for wind to whistle through and no leaky spots. The whole thing just feels solid.

Also noticeable, which was a bit weird for me at first, was the temperature change. In February when normally everything is freezing, there were days when the greenhouse was sitting at 19 degrees C. Really!!!

So I guess from here on it’s a case of watching and comparing to previous years, but so far I can definitely say that yes there is a big difference between glass and polycarbonate, but, glass is expensive so if it’s not an option for you, polycarbonate just might be.

Just for a bit of daft fun, here is the other use we made of the greenhouse at christmas…

A greenhouse update: spring 2019

There was much excitement when we replaced that rickety old polycarbonate greenhouse with our shiny new glass one, but it was excitement about having a new toy rather than of what was to come, because at that point, we really didn’t know what to expect.

So since it’s spring and we are actually using the greenhouse now, I thought it might be time for a wee update on how we are getting on and what we think of our new toy.

First thoughts


Well the first thing I notice is that the glass greenhouse seems to take the heat a lot quicker. We are seeing the automatic windows opening way earlier in the season that we did previously and the greenhouse generally does feel warmer. Probably because it doesn’t have a howling gale going through it and rain seeping in. Yep you read that correctly. The old greenhouse was never quite water or wind tight. This one however, feels solid!

It’s not yet at the point in the year where the temperature is unpleasant in there, but there is a marked difference between outdoors and inside the greenhouse. Can’t wait to see how this changes as the weather changes.


Also it seems to stay clean which is a crazy thing to say because obviously I didn’t get a free shift of elves with the greenhouse sale who come in during the night and clean up. Or did I?

Check out youtube to see the naughty elf in the greenhouse.

But it does, it seems to stay clean. The glass is still clean. The old polycarbonate greenhouse got taken apart and cleaned every year because green sludge built up everywhere, also the polycarbonate discoloured badly.


I also feel like I’ve got way more space, even though it’s exactly the same size. I don’t know if this is because I have more headroom in this one, but it definitely feels bigger.

There is also one thing which makes a huge difference but it’s not exactly the greenhouse. The new staging. I used to use cheap and nasty wire shelves which to be honest weren’t really much use for anything other than storing things but the new staging is really solid and practical so I can actually use it for potting on etc. It just makes the whole space feel more useable.

I am really happy pootling away in there and I feel like I can pootle and do so much.


One of the things that’s new and a bit exciting is that I can now hang baskets inside the greenhouse. Before I had to do a kind of magic balancing thing with an upside down stool but the new greenhouse, apart from being really solid, has rails for hanging stuff. Means I can have the baskets in there while the plants mature a bit and grow.

Only downside though, I keep forgetting! They are hanging just a t my head height.

Greenhouse calamity – the wind has it’s way

Well winter seems to have finally passed and I couldn’t be more thankful. We didn’t exactly get battered with snow but Musselburgh saw a couple of nasty storms and the garden, mostly the greenhouse took a hit.

Greenhouse  wind damageWe’ve been lucky in the past when the strong winds have taken roof panels from the greenhouse, we usually found them the next day in a neighbour’s garden. This time however they were long gone so we had to shore things up with cardboard and gaffa tape until the storms passed and we could fit some new polycarbonate panels.

It really was looking in a sorry state and not just

the lost panels, inside took a battering too because the wind was then able to get in and pots were smashed, shelves knocked over and general mess and debris everywhere.

There was a lot of clearing up to do, not just inside the greenhouse but the panels had gotten all covered in crud thanks to the storms so we jumped at the chance for a bit of a clean up and overhaul on the first calm day we got. It was calm, with no winds which meant we could get the new panels in place, but it was blooming freezing and washing things and having your hands in water was not fun.


cleaning and repairing the greenhouse

It was worth it though. It only took a couple of hours to wash the greenhouse down, take the panels out of the frame and wash them (including washing any green yuk out of the corrugated insides and then put everything back together with its new panels. It also gave us the chance to empty it out and give the inside a good tidy up and a sweep and get everything spick and span again.

The best part of being that it meant we were ready to go today when we started getting things planted up for the first time this year, the greenhouse was practically palatial.

spick and span