A question about polytunnels compared with greenhouses

[organic]

I believe this can be a hot topic, but I'm not hoping for a "which is best?" discussion here.
Apologies if this has been covered elsewhere, but my initial search for info hasn't really answered this question.

As some of you will be aware from my other posts, I've just got a half plot. I'm playing around with different plans for my allotment. On some of them I've left space for a greenhouse... they aren't exactly cheap though.

I'm now thinking about making a polytunnel to fit the space (I'd use this method User Pages Preview / Save ) but this has raised a question:

Is there anything I'd use a greenhouse for that I couldn't do in a tunnel?

I intend to grow things like peppers, chillies, tomatoes and so on, and would also use it to get things started early along with some cold frames and maybe a hot frame too.


So, is a polytunnel suitable for that kind of thing?
I'm aware of the ventilation issue, I'm just wondering about the limitations of the design.

Anyone?

[Two_Sheds]

Is there anything I'd use a greenhouse for that I couldn't do in a tunnel?

Can't think of anything...

[organic]

So, they are ok for growing tomatoes in rather than just starting them there early?
That's handy.

[marathon]

I'm south west so maybe a bit warmer and I've been picking tomato's in the first week of June with cherry tomato's even earlier. My tunnel is just as full during the winter as it is during the summer.

The only difference i would say that there would be is the night time temp but so far I've outdone all the greenhouses on my site.

[kentvegplot]

The plastic on a tunnel doesn't 'hold' the heat as well as glass (or acrylic) in the greenhouse so it gets colder (and heats up faster too). If you're trying to keep things frost-free, a greenhouse is easier to heat and insulate (although I did rig up some bubblewrap in my tunnel one winter, and it worked). I grew tomatoes and peppers all summer in the tunnel, although you have to watch the ventilation (not many automatic vents available for tunnels, as far as I'm aware!)

[organic]

Well, unless I can get a greenhouse for free or very cheap my only option for the time being is a polytunnel. It's good to hear I'll not really be limited to getting things started in there.

I've got a couple of ideas on the ventillation front, none of which are particularly well thought out yet, but with a bit of thought I'll have a better idea of whether or not it will work.

I suppose I could just use fleece or something inside to help slightly less hardy things through the winter and just do without the really delicate things for the time being.

[Norm]

You could try building a poly/greenhouse! 2"x2" frame, the size of the greenhouse you want and cover it in polytunnel plastic. Put a door in one end and a window in the other for ventilation. Job done! If you want to be really posh, don't attach the plastic at the bottom, make it like a roller blind and cover the lower sides with enviromesh so you can have the plastic down in the winter and rolled up in the summer. You can also fasten bubble wrap inside during the winter for extra warmth.

[j r hilton]

Have you looked on your local free cycle site to see if any one is getting rid of a green house. Some people on the vine have managed to get a greenhouse for nothing this way.

[sewer rat]

Is there anything I'd use a greenhouse for that I couldn't do in a tunnel?
I intend to grow things like peppers, chillies, tomatoes and so on, and would also use it to get things started early along with some cold frames and maybe a hot frame too.
Anyone?

I have a greenhouse at home and a tunnel at work, with access to another two heated greenhouses at other gardens. I use the heated greenhouses to start some plants off - early lettuces which are transplanted into the tunnel, celeriac and celery which have long growing seasons. I also use a heated propogator to start off toms and chillies early - again for transplanting into the tunnel when they are big enough and the night time temp is satisfactorily high. Other than that I start everything that is not direct sown in modules in the tunnel - this includes all my brassicas, more lettuce, runner and french beans, aubergines, leeks, courgettes, cukes, scallions and even some of my beetroot.
Your tunnel should extend your growing season by at least 6 weeks - making your growing season arrive three weeks earlier and finish three weeks later - this will obviously vary depending on where you are in the country as well as from year to year but is a rough guide. As has been mentioned in earlier replies - tunnel will heat up quicker than a greenhouse, but will cool down equally as quickly, but we're nearing the end of October and my chillies are still flowering and fruiting, and my toms are still flowering and ripening, so the tunnel works for me and it can get pretty cold up here .

[organic]

john, I've had an ad on my local group already, but after you asking I've re-posted it. Maybe I'll be luckier this time around.


Rat, thanks for that detailed reply.
Mainly for the ease of heating and ventilating a greenhouse I think I'll hold out for glass for the time being. If one isn't forthcoming before Jan or Feb I'll start getting the necessary bits and bobs together to make a tunnel.

[j r hilton]

Hope you are organic. All the best.

[Duronal]

hi there, i own a tunnel on my allotment and it's still producing tomatoes - the 1st fruit was in may.

Chillies, Peppers, carrots, onions, sweetcorn were all super early in the tunnel. Avoid growing flowers too near to the tomatoes as they'll turn into triffids. (they possibly do this by thieving the tomato food). I'd suggest watering into pots to keep down on weeds and concentrating your watering to the roots of the plants.

My ginger plant has also thrived, as has the lemon grass, basil, and i the warm loving plants. Lots of cucumbers this year.

the only issue is tha i haven't developed a self watering system yet But i did manage to get a working gutter into barrels for rainwater. this winters job is to plumb in the barrels to a seep hose or create reservoirs under the planting beds. It's all just a question of how.

[Hans Mum]

my toms are still going in the poly as are the peppers and chillis. The other thing i think is at the lottie there is no glass to get broken, I know the poly cover can get torn but its (i thnik) easier to repair

[bravo2zero]

No limits

Theres nothing you cant do in a tunnel that you cant do in a greenhouse.Theres a book called Gardening under Plastic by Bernard Salt that i have found invaluable. My tunnel is 20x10 and ive had for 5 years now and it the best thing i have bought for the garden, my only regret was that i could have bought a wider one had i planned its position better.

[Premier Polytunnels]

Hello.

Hope you are well.

Polytunnels are a cost effective replacement for a glasshouse and they offer lower maintenance - and there are no panes of glass to break! Because modern polytunnels tend to come with one complete polythene sheet as standard, they offer less draughts.

With regards to ventilation, many polytunnels comes with ventilation netting in the doors. You can also choose to have ventilation netting down one or both sides of your tunnel. People do wonder how to cover this net ventilation up during the winter and the cheapest way is to pin some bubble wrap over it, or some spare polythene.

If you are worried about heating your polytunnel, I would highly recommend you purchase Thermal Anti Drip (or Anti Fog as it's sometimes known) polythene, which is the ideal cover for the UK weather and the one that most people go for. The thermal effect of this film is designed to stop heat being lost from the polytunnel.

You can also heat a polytunnel the same as you would a glasshouse, with a gas or electric heater.... Just make sure the heater isn't directed at the polythene!

You might like to check out 'The Polytunnel Handbook' by Andy McKee and Mark Gatter, which offers great advice including planning, siting, erecting, using, and maintaining. It might give you some good ideas as to what materials to look for, etc, with regards to building your own tunnel.

Have a good weekend.

Deborah (Premier).