Allotment Gardening Advice Help Chat

Growing => Grow Your Own => Topic started by: DHM on September 26, 2018, 08:11

Title: Tethering a Polytunnel?
Post by: DHM on September 26, 2018, 08:11
Lucky us, we're about to inherit a FREE 10x8ft  polytunnel from a friend who's turning in their plot. Haven't seen it yet but the tubing is said to be black so assume its plastic rather than metal.

Given that our flat, exposed site is prone to flying greenhouses in high winds, I was wondering if anyone knew how best to tether a potentially lightweight polytunnel to the ground?
Title: Re: Tethering a Polytunnel?
Post by: sunshineband on September 26, 2018, 08:37
You will never look back!!

We stake ours inside on each corner with a fence pin at least 30 cm into the ground and cable-tie the frame to it top and middle

The cover needs to be trenched in. Do not listen to anyone who says you can weight it with slabs etc as A) It rarely works and allows too much "play" on the cover which then wears through and tears away and B) soil is free!! Dig a trench around the outside perimeter of the frame about 20cm deep, into which the excess cover hangs, before re-filling it and treading it down firmly.

Attach the cover to the  frame with its velcro straps... these are stronger than they look!

Make sure the door cannot blow open if it is a hinged one. Most of these small tunnels have a zipp door, and this is usually the first bit to "go" to check the zip is running freely: WD40 can help but keep it off the cover


Check the cover for small holes and repair even the smallest using proper repair tape applied inside and out when the material is dry

Ensure nothing is chafing against the cover either inside or out, as this will wear a hole eventually

And your tunnel then has the best chance of staying put  :D
 We had one this size for six years before the cover became too worn to be repaired, then we went for a larger model and repurposed the frame to a fruit cage, and out site has gale force winds regularly
Title: Re: Tethering a Polytunnel?
Post by: DHM on September 26, 2018, 08:58
Sunshineband thanks for your detailed response, I'll follow your instructions to the letter!

She said the door had been 'removed' by whoever had it before her (sounds like a multi-gen handmedown!) so my guess is it's a proper door rather than a zip-up, so might have to mock something up out of some scrap wood. Looking forward to setting it up but where its going to go is proving a bit of a headache!
Title: Re: Tethering a Polytunnel?
Post by: sunshineband on September 26, 2018, 09:15
Then the frame is likely to be metal.  A door frame is easy enough to install and if you are adding your own door you can then choose which way to have the hinges... having it so that from the inside it opens against the prevailing wind works best we found.
Title: Re: Tethering a Polytunnel?
Post by: DHM on September 26, 2018, 11:45
Now I'm hearing it WAS a zip-up but someone added a door... sounds like a laugh...

Current train of thought is put it on the tomato/pepper bed then move it each year with the rotation. Would mean losing some growing space, but if I had blight issues like this year it would help halt the spread to the potatoes perhaps...
Title: Re: Tethering a Polytunnel?
Post by: sunshineband on September 26, 2018, 12:42
Now I'm hearing it WAS a zip-up but someone added a door... sounds like a laugh...

Current train of thought is put it on the tomato/pepper bed then move it each year with the rotation. Would mean losing some growing space, but if I had blight issues like this year it would help halt the spread to the potatoes perhaps...

I found that when Late Blight struck, it affecte the tomatoes in the tunnel as the spores came in through the mesh vents  :(
Title: Re: Tethering a Polytunnel?
Post by: mumofstig on September 26, 2018, 16:07
Now when I had a polytunnel, I never got blight, but did seem to get botrytis because it tended to get steamy inside  :lol: so I was often snipping  off leaves and fruits that were rotting at the stems  :lol:
Title: Re: Tethering a Polytunnel?
Post by: DHM on September 26, 2018, 17:00
Given more thought, and with whats been said taken into account, probably best to find a permanent location for it.

How do you guys with smaller PTs work things like crop rotation? I was initially going to use it for seedlings then plant Toms, peppers and chillies in it but they're all part of the same growing family and theres not tonnes of room in 8x10ft PT. Do you grow the same stuff in it every year?
Title: Re: Tethering a Polytunnel?
Post by: Plot 1 Problems on September 26, 2018, 19:00
Mines slightly larger (10' by 20' approx) and I have three beds that I try to rotate between. One bed will have Toms and basil, one chillies and sweet peppers and the third has other stuff like melons, aubergines and things in. It get's cramped in there late summer but it works.
The pic is mine currently with winter salads and brasssicas in, plus the chilli plants which are still going strong.
Title: Re: Tethering a Polytunnel?
Post by: sunshineband on September 27, 2018, 09:12
When I had the small one, I used to plant tomatoes on alternate sides one year then the next, and Peppers chillies etc on the other, with mustard greens and a couple of Spring Cabbages following the toms in the Autumn, and a row of dwarf french beans in the Spring along the front of the previous year's chilli bed (Where toms then went in early May, behind them. Very early mangetout always went along the short bed at the back, where I'd plonk one cucumber plant afterwards

Now I have two 6mx3m tunnels, a metre apart, with four long beds, which have a four year rotation: sheer luxury, especially as the space in between the two is covered with fine netting and the back doors facing each other then stay open all Summer, giving a 13m tunnel with extra ventilation.


Title: Re: Tethering a Polytunnel?
Post by: DHM on September 27, 2018, 10:10
Sounds lovely Sunshineband, if we go for another plot next year we may consider something similar!

Plot 1 Problems, that looks dreamy, given me the idea of having a 2ft central bed, 2ft beds against the side walls and 1ft wide paths around... mind you I'll have to see how big it 'really is' when built!

I plan to use it for raising seedlings then if I go for a 3 bed option, follow with a cucumber, then experimental toms, peppers and chillies. Ill let you know how it goes!
Title: Re: Tethering a Polytunnel?
Post by: sunshineband on September 27, 2018, 14:02
Sounds lovely Sunshineband, if we go for another plot next year we may consider something similar!

Plot 1 Problems, that looks dreamy, given me the idea of having a 2ft central bed, 2ft beds against the side walls and 1ft wide paths around... mind you I'll have to see how big it 'really is' when built!

I plan to use it for raising seedlings then if I go for a 3 bed option, follow with a cucumber, then experimental toms, peppers and chillies. Ill let you know how it goes!

Just remember that some plants, chillies are one, bush out quite wide and you might find yourself struggling to walk along the paths by mid-Summer. We left a 90cm path down the middle for our little tunnel, with two beds then 1,10cm wide, plus a third bed across the back that was 1m 20cm wide, and had three beds that way.
 But you are right... you need to see it in situ first before deciding


Title: Re: Tethering a Polytunnel?
Post by: Plot 1 Problems on September 27, 2018, 16:14
Sounds lovely Sunshineband, if we go for another plot next year we may consider something similar!

Plot 1 Problems, that looks dreamy, given me the idea of having a 2ft central bed, 2ft beds against the side walls and 1ft wide paths around... mind you I'll have to see how big it 'really is' when built!

I plan to use it for raising seedlings then if I go for a 3 bed option, follow with a cucumber, then experimental toms, peppers and chillies. Ill let you know how it goes!

Just remember that some plants, chillies are one, bush out quite wide and you might find yourself struggling to walk along the paths by mid-Summer. We left a 90cm path down the middle for our little tunnel, with two beds then 1,10cm wide, plus a third bed across the back that was 1m 20cm wide, and had three beds that way.
 But you are right... you need to see it in situ first before deciding
That's very true, It was hard for me to get around parts of the tunnel mid-summer with the narrow paths, but I did cope ok. Not sure I'll be wanting to do it in ten years time though ;)
Title: Re: Tethering a Polytunnel?
Post by: AlaninCarlisle on September 27, 2018, 18:39
The opening post asked about tethering it, I found the only satisfactory and safe way in this windy county was to dig a 9" trench all around the perimeter and to bury the sides and ends of the polythene in that trench
Title: Re: Tethering a Polytunnel?
Post by: AnneB on September 29, 2018, 13:15
On the subject of doors, we have quite a large polytunnel on a metal frame that was given to us.   We had a ready made dwarf brick wall on the plot and anchored the frame to that using very strong bolts.
We have made a door frame with the intention of adding a door but never got round to it.  At the other end we have put in two small opening windows, which remain open all the time.
This year I think it helped, the tunnel didn't get completely boiling compared with others on site.  So we have decided to leave it like that. 
Title: Re: Tethering a Polytunnel?
Post by: rustyspade on September 29, 2018, 13:51
Would recommend that you consider not only a door but also a 'flyscreen' door with mesh to keep out birds (and cats) when you wish to have a open door for ventilation/temperature control.Make it wide enough to permit  your wheelbarrow etc.
Title: Re: Tethering a Polytunnel?
Post by: DHM on September 29, 2018, 20:09
Collected it today, very happy! It' 3x2m so a bit smaller than expected but it will fit better into the space that way.

It's a metal frame, a bit rusty but plenty of life left. The cover however is aftermarket, one of the green mesh zip up types and the 'door' is basically both of the short sides repeatedly, vertically slashed to create like fly strips. The cover is not in good condition but it was free so wont moan.

So, do I fit a doorframe/door and wrap it in polythene, or buy a fitted replacement cover? The current one will certainly make an emergency spare.