Polytunnel potatoes - advice for a novice please!

[becky_jo]

Hello all of you who are probably far more experienced than me...!

I am into the second year of polytunnel exploration and after some successes and a few failures last year, I'm trying out some new crops. I planted some potatoes (rocket and king edwards) a few weeks ago and they have shot up! I did try to plant them in rows but now they just look like a small jungle!

I have been reading about earthing up, and have been trying to do so. However they keep getting taller and I'm finding it hard to keep up. I know it's to avoid too much light reaching the tubers, but will the pretty dense canopy be shading them enough, or do I need to keep adding more soil/compost around the stems?

Does it matter if they look a little overcrowded? I tried to upload a photo but can't seem to do so without a url, so any advice on this too would be appreciated!!

Thanks,
Becky

[bario1]

Hi Becky and welcome!

I wouldn't worry about overcrowding, they are naturally large sprawling plants. But to help us advise you, can you tell us how far apart you planted the seed potatoes?

As for earthing up, it's optional really - i never bother, I just plant my potatoes deeper in the first place. How deep did you plant yours?

[Jungle Jane]

The leaf growth isn’t enough to stop the potatoes going green,how much soil have you earthed up with already,they always grow taller,you could add two foot of soil & they’ll still be growing taller. Is it difficult to reach to earth them up? Try to earth up as much as you can,the worst thing that would happen is you get a few green potatoes but you’d also get edible ones.

[nickdub]

I wouldn't worry about the overcrowding - you'll definitely get a crop. You do need to earth up if the new potatoes are near the surface - if you have any old grow-bags or leaf-mould knocking around you could use compost etc brought in to your greenhouse to put over the roots of the plants

[becky_jo]

Thanks for your responses!

I think I followed some advice from somewhere (either on the net or the seed potato packaging), but maybe only loosely as I found it hard to anticipate how big they were going to grow! I think I aimed for rows about 8 inches apart, and 3 seed potatoes in a row (approx 6 inches apart). They don't seem to have sprouted exactly where I thought I put them, but thereabouts. As for how deep - I think I aimed for about 5 or 6 inches deep, and have been earthing up another few inches especially around the larger plants (sorry a bit vague). I guess I can just continue piling compost around them. They aren't difficult to reach as such, just hard to earth them up without spilling it all over the leaves!

[Jungle Jane]

I read a study last year that said for best yield plant the seed potatoes 12” apart but I never used to do that,I’ve probably planted them that close before & always got potatoes. It is difficult without spilling soil on the leaves,it’s a bit of a delicate job. The growth sounds good & they’re spreading out for you to have more potatoes,thoughtful of them

[WalterWhite]

I hope you have adequate ventilation in your tunnel. Even with open doors the tunnel can reach high 30's Celsius in summer.

[becky_jo]

I hope you have adequate ventilation in your tunnel. Even with open doors the tunnel can reach high 30's Celsius in summer.

Yes we have big vents along the sides that we roll up every morning, and can hook the door open if necessary. I'm always blown away how hot it can get in there!

[Aberdeenplotter]

Strikes me that it's a waste of valuable indoor growing space growing something in there that is perfectly happy growing outdoors and spuds are much easier to control outdoors too

[Doncasterpaul]

I have also tried early potatoes in my tunnel this year. And the exact same thing has happened. So it has been helpful reading your post

[becky_jo]

Strikes me that it's a waste of valuable indoor growing space growing something in there that is perfectly happy growing outdoors and spuds are much easier to control outdoors too

I'll bear that in mind next year!

[nickdub]

There's a case to be made for growing potatoes inside at odd times of year - for example so you can have some new potatoes at Xmas. But as has been said its easier to grow them outside in the Summer - you can do some in bags to start them inside, then move them out when you need the inside space for tomatoes or whatever - which is what I have done this year.

Some people have grafted tomatoes on top of potatoes, as a get two crops form one plant strategy - I've not tried this myself.