Polytunnel Covers

[bill_j_smith]

Hi

Forgive me if this subject has been covered before (I couldn't find any references to it though); I am looking to buy poly-tunnel and most of the ones I see have a green cover, I would have thought that a transparent cover would be better - opinions?

Regards

Bill

[vegpatchmum]

HI Bill,

First of all welcome to the boards

I run a gardening club at our local school and the school has a polytunnel with a white/semi-see through cover on. If you think about how hot and intense greenhouses can get and the need to provide shading for the plants in the height of summer, I'd say that the polytunnel covers are produced with an element of 'shading' built in - well that's what I've always thought and the plants grown in the tunnel last year did ok, so I'd say the semi-transparancy works

Someone with a more technical understanding of these things will undoubtedly be along soon and will hopefully shed more light on the matter (if you will excuse the pun )

VPM
x

[peter]

Do you mean a true polytunnel. i.e. a big thing, or something big enough for one to four growbags.

Green cover sounds like those smaller items, where the cover is green net sandwiched between polythene films & heat bonded.

[vegpatchmum]

Ohhhhhhhh See my ignorance coming out again - never even thought about those types of tunnel - sorry Bill

VPM
x
(off to find a quiet corner somewhere and contemplate this further evidence of brain malfunction )

[bill_j_smith]

The polytunnel in question is 3 metres in length, 2 metres in width and 1.9 metres in height - a standard gardeners polytunnel I would have thought (though I admit I could be incorrect).

[peter]

Yup a (smallish) big thing.
Does the cover consist of plastic film/sheet, or does it have a thready net in it?
Have to say all polytunnels I've seen are basically clear plastic, except (only seen pictures) the Keder ones.

[bill_j_smith]

Hi, link to aforementioned polytunnel:

http://www.charliesdirect.co.uk/products/gardman-waterproof-polytunnel-
with-windows

Unsure as to how the cover is constructed, perhaps you can tell by the picture?

[peter]

That is not really a polytunnel.

Take a look at what Geoff has been building in this thread Subject: Polytunnel Choices
It will have a clear plastic membrane stretched over the framework.

[alan refail]

http://www.charliesdirect.co.uk/product ... th-windows

I would agree with Peter. It is not a polytunnel, rather a large cloche. I'm not sure what use it would be and I wouldn't trust it in windy conditions. Not for serious use I shouldn't have thought.

[bill_j_smith]

I understand when you say it is rather small; however, I cannot afford anything bigger (cannot justify >£100) and so, back to my original question of green covers - are they any good?

[alan refail]

and so, back to my original question of green covers - are they any good?

Bill
I think the answer will depend of what you intend using it to grow and at what time of the year.

[bill_j_smith]

I guess I am looking at Spring to late Autumn; the reasoning behind this is I have just found a top link for building your own polytunnel:

(http://www.overthegardengate.net/UserPa ... nel&Page=1)

so I am thinking of using the one my original question was about until the Autumn then having a go at building my own as per the link. I already have a large greenhouse so I can utilise that for growing veg over the Winter (yes, its heated).

Regards

Bill

[alan refail]

This home-made tunnel has been discussed a few times on the forum since 2005. Pity is that as far as I recall none of the intended builders reported back on progress. Did they give up? Try a forum search for Homemade polytunnel (or in one case Polly tunnel).

If I were you I would definitely contact Alan on his website and ask how his survived.

[sally wright]

Dear Bill,
a friend of mine has one of these and it works well but I think that she is on to her second cover now. I think it lasted around 5 years. So on that basis I would say these things.
Get some anti hot spot tape and use it on the frame. This will avoid the chafe that did for her cover.
Also keep the zips as clean as you can and take the cover in for the period Nov to Feb to avoid the worst of the bad weather. You could still use the frame for covering your brassicas using a piece of net over the top.
Keep it as clean as you can (soapy water) as the light transmission is not as good as glass.
Tomatoes are not really very good in one as it is a little bit too humid and dark for them to do really well in one.
Make sure you get one from a specialist supplier (not from the back pages of the morning paper etc as the replacement covers are not usually available for these ones.
Regards Sally Wright.

[Westi]

I bought that one as well but it blew away (nearly took my neighbour for a short flight when it did as he was trying to save it) It went the first night it was up and it wasn't a gale or anything, just a bit of a stiff breeze.

I had nailed all the bottom frame onto wooden battens and that stayed but most of the other pipes buckled & I couldn't slot the ends back together. I have managed to put it back (Westi style) to the first row on the sides without the top hoops and have put some polycarbonate sheets around the sides and use it to grow my toms & stuff and it protects from wind and does warm the plants closest to the walls a bit I think.

The cover was retrieved but had ripped all the seams so cut that up and use it to throw over hoops on rows when a frost is forecast so not all wasted. Doesn't answer your question of course but if I don't get down to lift it off the plants seem to thrive quite well as does let in some light but it is more likely the warmth created that produces the growth.

If you ever have the same misfortune this may provide another solution. Me - I saving for a real one now we're allowed to have one but confused.com doesn't come near - can't they just quote one price on website without all the bits being extra - I haven't a clue what they are on about or what I'd need.

Westi