Polytunnel shading

[pigletwillie]

In an effort to provide some shade in our new tunnel , Tigger suggested growing cape gooseberries on wires over the tomatoes, aubergines and peppers.

Could this idea be adapted to use cucumber plants to trail over rather than cape gooseberries.

Height isnt a problem as the tunnel is 9` high but is oriented east west to catch maximum light.

[peter]

Sounds sensible Piglet, surely it would apply to any trailing crop, even squash if you can support the resulting fruits. Wasn't there a chap in KG grew all sorts of stuff over the outside of his glasshouse for shade with some sort of temporay frame?

Regards, Peter.

[pigletwillie]

He did it to a greenhouse I think but I dont want all that palava as my tunnel is 9 ft high and 25 ft across the hoops.

[Chantal]

You could grow vines Piglet; then make your own wine. Chateaux Piglet. It would wash those snorkers down a treat!

[peter]

Piglet, I meant for you to check WHAT he grew rather than HOW.
Regards, Peter.

[richard p]

are you sure the tunnel needs shading? dont tomatoes need all the light they can get? weve had people claiming that greenhouses are better than tunnels becaus the glass lets more light in than plastic. bear in mind the plastic does transmit less light as it ages.

[Johnboy]

Hi Piglet,
I have a Passion Flower planted in each corner in one of my 60x30 tunnels and they even have to be cut back at times. Because this tunnel was not used for the last two years they went absolutely mad and they even took over the floor space. About a month ago I had to go in and cut them back and one main stem that had established itself across the floor was almost 50 ft long. The growth was such that it took me ans entire day to get it back under control. At the begining of the season you look at them and you think they have died over the winter. How wrong can you be and now they are just coming into growth again. This is ideal because when the shade is most needed they have grow sufficiently to give super cover.
Originly they were grown for cuttings which I used to market but if you need any I can very soon take some cuttings but sadly they will not be ready until the Malvern Autumn Show time. That offer is open to all so if you need some plants let me know shortly.

[Tigger]

I've planted 4 vines (eating grapes) in one of my tunnels as an experiment this year, one in each corner and will grow them along wires to shade peppers, aubergines and chillies. I saw this in some of the Herefordshire Vineyard man's tunnels last year. He groes vines across the top and tomatoes underneath.

As Piglet says, in my other tunnel, I'm going to try growing cape gooseberries to shade the tomatoes.

In my experience, you certainly benefit from shade in the tunnels during July, August and early September. It cuts down on the watering and makes it bearable to go in!

As for using cucumbers as shade - my only doubt is that they need the shade too, so I don't know how good they would be as the 'provider'. This year, I'm growing my indoor cucumbers up lengths of shade netting that I've positioned from the back or each mini raised bed to the central pole of the tunnel.

I have, in the past, grown annual climbers over the tunnel, as Peter suggests. These are easy to remove at the end of the season. You have to plant them either side and hope they'll meet over the top. The only problem is you have to provide something for them to get some purchase on in order for them to know where to go - like some strings - which I found very fiddly.

[Allan]

To be effective in cutting down the peak temperature on greenhouse or tunnel you have to stop the sun getting into the structure, once inside it heats up to the same amount whatever you have there so shading ought to be on the outside. Plants such as grapes or passion flowers can only lower the temperature by evaporation which is not the way to do it.
Unless you are prepared to fork out large sums of money Varishade is probably the best bet but it depends for its action on the wet/dry cycle.
Allan

[PT]

I put some roof vents in a tunnel at the HDRA Yalding. One at each end of the tunnel. Unfortunately it is in the staff only bit. But you can ask to see them.
It definitely kept the temp down. They had automatic vent openers which meant not constantly keeping an eye on the temp. It's best to put the vents in before you skinning the tunnel, but can be done after.