Sallygarden Smallholding - The Forum For Sustainable Living

After many months of thinking about it I've just ordered a polytunnel and am now panicking about how to get the site ready. I'm fairly happy with the instructions I have for the erection of the tunnel itself but it's the siting and the preparation of the growing area I'm not sure about. I've had a greenhouse before though that was in a small urban garden in England, this is a 14ft x 20ft polytunnel on a windy hillside in Donegal! Any advice on the following would be gratefully received:

- I'd planned to site the tunnel north-south so that the sun moves evenly across it as the day progresses. The guy selling me the tunnel suggested it should be east-west as this would cope better with the westerly winds. Any thoughts?

- I've stripped the turf off the top but now not sure whether to dig the ground over or simply rotavate. The ground doesn't seem to have been cultivated for some years.I know I should really double dig and add lots of farmyard manure but I'm trying to reduce the hard labour a bit.

- Should I go for three beds wide or two?

Thanks

You have a little bit of hard work in front of you but I'm sure the benefits will be more than worth it. I can tell you what we decided for our situation, hopefully others can chip in with their experience too.

- orientation
Our tunnel is east west too, but in our situation its because of the size of our field, the tunnel wouldn't fit in north south. Also if NS our tunnel would have been shaded by large trees. In the summer its in full light all day and we are delighted with its performance. Our site is sheltered so I can advise on windy sites, but what you say makes sense.

- beds
our soil is clay so we had to dig through manure, lime and sand to break it up. If your soil is peat you could try just digging in your fork prongs, then leavering the soil up but not out, so air can get down more easily. Then spread out your manure, cover with a mulch, and leave it till spring. Hopefully the worm will do the majority of the work. If not, you could then dig as you need it. Maybe you could dig a small percentage thro now incase the worms don't do the business. Just thinking out loud.

- how many beds
I'm not very good an envisaging the size of your tunnel but what you need to consider is ;

make sure your footpaths are wide enough to walk down comfortably, and kneel in when working on the beds, and make sure a wheel barrow can fit down the path too. My path is the width of 2 of my feet (size 5 shoe)!.

make sure the beds aren't too wide. Ours are about 3 foot which work well. Its just a little too wide to step across without standing on the bed which can be a bit of a pain walking all the way around the paths to get to a foot away from where you started!

Last but not least there are a couple of good books, and a few very poor books, on polytunnel gardening. They are hard to find on amazon as the word polytunnel is not included in their title, but via word of mouth try ...
Gardening Under Plastic, and Four Season Harvest both available via the sallygardens bookshop at http://astore.amazon.co.uk/aniricragool ... TF8&node=7

All the best with your venture, come back with any more questions, or enlightenings you experience to share with others.
Rebecca
ps as well as our blog at sallygardens.typepad.com theres another that has excellent information on polytunnels and written with a fantastic sense of humour ... visit Hedgewizard at
http://www.hedgewizardsdiary.blogspot.com/

You have a little bit of hard work in front of you but I'm sure the benefits will be more than worth it. I can tell you what we decided for our situation, hopefully others can chip in with their experience too.

- orientation
Our tunnel is east west too, but in our situation its because of the size of our field, the tunnel wouldn't fit in north south. Also if NS our tunnel would have been shaded by large trees. In the summer its in full light all day and we are delighted with its performance. Our site is sheltered so I can advise on windy sites, but what you say makes sense.

- beds
our soil is clay so we had to dig through manure, lime and sand to break it up. If your soil is peat you could try just digging in your fork prongs, then leavering the soil up but not out, so air can get down more easily. Then spread out your manure, cover with a mulch, and leave it till spring. Hopefully the worm will do the majority of the work. If not, you could then dig as you need it. Maybe you could dig a small percentage thro now incase the worms don't do the business. Just thinking out loud.

- how many beds
I'm not very good an envisaging the size of your tunnel but what you need to consider is ;

make sure your footpaths are wide enough to walk down comfortably, and kneel in when working on the beds, and make sure a wheel barrow can fit down the path too. My path is the width of 2 of my feet (size 5 shoe)!.

make sure the beds aren't too wide. Ours are about 3 foot which work well. Its just a little too wide to step across without standing on the bed which can be a bit of a pain walking all the way around the paths to get to a foot away from where you started!

Last but not least there are a couple of good books, and a few very poor books, on polytunnel gardening. They are hard to find on amazon as the word polytunnel is not included in their title, but via word of mouth try ...
Gardening Under Plastic, and Four Season Harvest both available via the sallygardens bookshop at http://astore.amazon.co.uk/aniricragool ... TF8&node=7

All the best with your venture, come back with any more questions, or enlightenings you experience to share with others.
Rebecca

And now she leaves me bait ...

Hmm. You're quite right that N-S gives maximum sunlight, but resistance to wind becomes quite important towards the end of the film lifetime and in heavy weather - I'd go with best attitude for wind. Don't forget to leave yourself 3' clear on all sides for installing and cleaning the film.

Levelling the ground doesn't matter end-to-end, but it's more important side-to-side as things get quite fiddly if the corners aren't level; remember though, it's only where the tunnel frame meets the ground that has to be levelled.

You haven't said what you'll be growing into specifically but I'm betting it's soil beds; so get any heavy digging out of the way now because it'll be MUCH harder when the skin goes on because you won't have room to swing a mattock. Ditto, moving barrowloads of soil around is much easier if you're not restricted by doors and paths; heavy work now will pay you dividends year after year once it's done.

Bed layout is determined by tunnel width for smaller tunnels, and you have to allow 18" for paths at least. Head height is greatest in the middle - so here's hoping you chose an 8' high model! If you had a central path that would leave you two beds of 6' depth - too far to work unless you use stepping stones, planks, or keyhole beds. Two paths would give you two side beds of 2' (a reasonable reach) and a central one of 4', which is what I use myself. Don't forget the central bed can't run quite to the doors unless you don't mind trampling the ends of it.

Other considerations are power (if you need it) and water; if you're watering with a can expect to spend about 40 minutes a day watering in summer so make sure your water source is nearby. A seep hose cuts watering time down to practically nothing.

Hope that's a decent start for you - the only book worth reading for now is Salt but if you've got any other questions, come look for me!

I wondered where you sourced your polytunnel? I have a small one here and the plastic has been on it 10 yrs!!! how about that!
I'd like abigger one like the one you got anyway...
My neighbour has 3 enormous polytunnels in a very exposed field His run north south. so the west wind hits the side. dont know if he planned that. no bother anyway. He laid black plastic entirely and plants into it. The way that really seems to work is he hardly has to water. and thats really something because this is the burren and it drains so fast. He grows grapes in one tunnel.
*Here wireworms are a big problen when you break new ground. My polytunnel was infested for years. I used potato traps and shut the chickens in for a week once a year.

Our tunnel is from Morris Polythene Greenhouses in Omagh.
So far so good, a year and plastic is still on ... 10 years must be a record!

Ten years isn't a record, it's a bloody miracle! Is the light transmission still good?