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My Cedar framed Greenhouse is now stuffed full of cuttings and overwintering plants and Iam concerned about the tremendous amount of condensation inside. Any advice or tips on how to reduce this would be welcome.


Increase the ventilation during the day - even leaving the door open on fine days until the ventilation has cleared. 


paraffin heaters produce a lot of condensation. I think that electric fan heeaters are best at reducing it, and ventilate on warm days.


Mine are condensating without any heating, I just open doors etc. on dry days, regardless of o/s temperature, I think better cold than damp. Don't think there is any answer as plants will give off moisture, as well as GH  condensating. So it's back and forth to GH.  


Iam going to give it try keeping the door open on dry days. I hope I don't lose any plants to the cold weather. By the way some insects or catopillers are eating some of my Pelegonium cuttings leaves but can never find the blighters, they must only come out at night.



If it's caterpillars they will be on the plants all the time.  What does the damage look like?

Dovefromabove wrote (see)

If it's caterpillars they will be on the plants all the time.  What does the damage look like?

And they will leave little poo pellets that are a give away...maybe it is Vine Weevil.

I have found that opening the vents and doors during the day helps condensation. Insulation (bubble wrap) does help - at least it stops it dropping on the plants. Since I put tin foil on the floor of the GH that has also helped reduce condensation in my GH.

I have tried to upload photos of my greenhouse to illustrate some of my problems but can't seem to add the relevant pictures when trying to insert from the photo icon.


Megga, there are people on this forum who can help you;(sadly I am not one of them); start a new thread about your probs with photos.


Megga, what device are you using to browse the forum?  Photo's also need to be less than 1MB in file size.

Hi All

I'am currently using my iPad to upload photos is this the problem.

I've got a good sequence of pictures installing my dwarf wall Greenhouse which I wouldlove to share with everyone. Plus easy, strong, durable shelvinconstructed from CLS timber.

Also I have put guttering all round the Greenhouse with a down pipe connected to an unwanted wheely bin behind the GH  place on top of 4 layers of bricks, left over from the dwaf wall, behind the GH so not seen. I've placed a scouring pad down the outflow pipe to collect fallen leaves, which is working perfectly.

I've always thought rain water is best for plants and seedlings but I read in one off my Gardening Books this is not so. Can anyone explain.



Hi Megga, yes, that's the issue - you can't upload photo's directly from an iPad.  However, if you use an app to upload them to a photo site like Photobucket, you can use the little tree icon and use the link to your photo and it will then appear in your post.

I always use tap water for seedlings as (in my opinion) it is less likely to contain spores of fungi which may cause damping-off disease.  However I always use rainwater once they have grown beyond the pricking-out stage.

As others have said, ventilation is the only way to reduce condensation.  I have a solar panel which powers 12V fans (recycled from old computers) and that works even in Winter.  However, it's an unheated greenhouse and I only use it to provide a little extra protection for a few less-hardy potted plants - they still get well below freezing in there but do stay dry which really helps.

A couple off days ago I took the bull by the horn and removed all plants and cuttings from the GH and insulated the inside with bubble wrap. This gave me the opportunity to check each plant before returning them. It might be my imagination but it feels quite cosy inside now. The condensation has reduced and on sunny days I now leave the door open. No more cold drips on me or the plants. Thanks to all for advice.


Humidity levels have been average high 90%+, average low 80% during November. God for summer plants but not good for greenhouses in winter. If you heat the GH that would make the temp inside the GH warmer and reduce condensation.


Why is it regarded as being better to bubble-wrap the greenhouse on the inside as opposed to the outside?



Because winter frosts and gales will rip the bubblewrap to shreds if it's on the outside - I cannot conceive of a way of attaching bubblewrap to the outside of a greenhouse that will withstand  British winter weather. 

why does my green house still have condensation when it  bubble wrapt it never happen before 


I can upload photos from my iPad.  It's my phone that doesn't let me.

Gives me ideas to bubble wrap inside of my garage

I have a few plants in front of garage window and a mini greenhouse inside the garage.  Garage door let's in some air but think the condensation will start to up.

Not really much yet though

I have  a double mattress in garage also wrapped up so ill have to try keep the damp air down. 


I'll try the bubble wrap window soon, butiwas thinking more when I've and frosts arrive.  Any other  tips


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