text: Does anyone know whether grapes can be successfully grown in a polytunnel?
  
  Our greenhouse is being demolished soon, and I'd like to move the mature grapevine that's in there to our new polytunnel.... it's currently dormant, so I think I should be ok to move it, however I can't find anything anywhere about growing vines under plastic....
  
  Cheers!
  
  "Its not who you are underneath, it's what you do that defines you" - Bruce Wayne
  
  A friend of mine has a grape vine growing in his fair sized glasshouse.I`m not sure if its the normal method but the root is planted just outside and the vine itself is trained to grow up in the rafters.
  
  Maybe make sure that when the fruit is almost ripe that there's enough airflow going through - you wouldn't want your lovely grapes getting spoiled by rot & if it's nice & warm & humid in there rot would just love to set in.... Also keep an eye on the canopy, grapes are very susceptible to sunburn! (sounds very strange, but I live on an organic/biodynamic vineyard & I've seen it in our outdoor grapes! )
  
  I think Kathleen gave the clue ... polytunnels tend to be very humid with a lot of condensed moisture on the polythene. It would probably lead to the fruit rotting unless you left the tunnel open at both ends all the time, which is possibly not a good idea if you have a windy site.Worth a try though if the alternative is to throw away your vine, if only to prove me wrong
  
  My other concern about growing grapes in the polytunnel is fear of the vines piercing the plastic. If you're really diligent about cutting off side shoots it's probably not a problem - we're not and they're woody little b*ggers which will rip plastic no problem.
  
  Maggie
  
  Never doubt that you can change history. You already have. Marge Piercy
  
  I am sure that before the days when Grapes were shipped into the UK all those that could, grew Grapes for eating inside large Greenhouse, so I believe the practice was quite normal, So why not in a pollytunnel, yes they are humid if the doors are closed but then in the summer who would close the doors.
  
  cherami wrote: So why not in a pollytunnel, yes they are humid if the doors are closed but then in the summer who would close the doors.
  
  Well I would.
  I've closed the doors on both my tunnels and greenhouses every evening so far this year, and they've stayed shut all day quite often as well. Not all of us are having record breaking temperatures (thank goodness), but sometimes it feels as if it's still winter even though it's a summer month.
  To get on topic, I planted a black grape in my tunnel last year and it has several bunches of grapes this year, so I'll let you know if the higher humidity has and bad influence on them ripening.
  I have a green grape vine in my greenhouse and that's pretty humid as well, but it doesn't affect the grapes at all, so I'm hoping I was wrong in my post further up.
  
  Even though it would seem we have nicked all your sun 31 here today and 42 ish in the tunnel, I tend to keep the doors open unless I know its going to be below 10, because whilst it's 10 outside it is always that much hotter inside. I have read some very conflicting notes on humidity some say it does not matter others say it does. Funny I find the drier it is the more I get an infestation of Flea beetle around my other plants which does tend to run over to my tomatoes. Last year because of the dryness I got infested with greenfly. So this year I have kept it as moist as possible but kept doors open.
  
  This is my first year of keeping eating grapes in the tunnel though for the last two years I tried to propagate some of the wine grapes I have, they did very well and in fact were hard to control, some grapes did go moldy before picking but they do that outside as well. Out of interest how are you growing yours, mine are running up high near the roof. I have watered mine as we have had no rain for, well I just cannot remember when but at lease two months, the grass is brown the plants outside are beginning to show distress, the wild plants too, we have no sloe berries at all. Please keep us informed how you get on with your grapes, I for one am very interested.
  
  Well, that's all right then. You got all our sun but we got all your rain.
  
  I bought two grape babies (I can't call 4" tall a vine) repotted them when we got them home and put them in the polytunnel. One of them died within a couple of days and the other has lost all bar one leaf but is just about hanging on. I have no idea what the problem is - are there special requirements by way of compost etc? I'm wondering if they were just sickly plants in the first place.
  
  Maggie
  
  Never doubt that you can change history. You already have. Marge Piercy
  
  Could have been a problem with the roots too short, may have needed some shade to begin with and of course some grapes just don't like certain climates, but the PT should have offset that problem. keep trying get some good stock in, I used http://victoriananursery.co.uk/ they have a good selection. I believe the Romans would have grown grapes in the north, so why not yourself.
  
  cherami wrote: I tend to keep the doors open unless I know its going to be below 10, because whilst it's 10 outside it is always that much hotter inside.
  
  The reason I close my tunnels is not the temperature but the wind. We have had gale force winds every week or two throughout this so called summer, and I don't want my tunnels to turn into wind tunnels.
  The new vine in my polytunnel is planted next to a side hoop and last year I allowed it to grow about 18" above ground level, each way along the side of the tunnel. This year I am training a rod to grow up the hoop it's planted by, and the 2 ends will be also grown up and over the hoops (when they reach that far)
  The vine in the greenhouse has 2 rods along the roof in the conventional way. The second rod is just starting it's journey on the right hand side. It looks happy.
  
  Did you check the roots for vine weevil grubs Maggie ?
  I'm not sure if you're trouble by such things up your way, but they are a lot more common here now and devastate potted plants, especially cyclamen.
  
  cherami wrote: I tend to keep the doors open unless I know its going to be below 10, because whilst it's 10 outside it is always that much hotter inside.
  
  The reason I close my tunnels is not the temperature but the wind. We have had gale force winds every week or two throughout this so called summer, and I don't want my tunnels to turn into wind tunnels.
  The new vine in my polytunnel is planted next to a side hoop and last year I allowed it to grow about 18" above ground level, each way along the side of the tunnel. This year I am training a rod to grow up the hoop it's planted by, and the 2 ends will be also grown up and over the hoops (when they reach that far)
  The vine in the greenhouse has 2 rods along the roof in the conventional way. The second rod is just starting it's journey on the right hand side. It looks happy.
  
  Greenhouse.jpg
  
  Now that explains a lot, your grapes in the greenhouse look very healthy and very large bunches, how much do trim back or do you just let it have it's way. I noticed up in the field I have the vineyard in, which I purchased some time ago that the vines that have been left to ramble and are climbing the Silver Birch tree's are the ones which look really strong and normally plenty of fruit, though the quality I am unsure about but they taste ok to me, though they are wine grapes.
  
  I have read so much conflicting stories about planting outside and inside it makes the mind boggle, but next to the hoop will get lots of good run off water (let us have some please).
  
  Odsox wrote:Did you check the roots for vine weevil grubs Maggie ?
  I'm not sure if you're trouble by such things up your way, but they are a lot more common here now and devastate potted plants, especially cyclamen.
  
  I'll have a look.
  
  Maggie
  
  Never doubt that you can change history. You already have. Marge Piercy