Kitchen Garden Forum

I will hopefully have my polytunnel up and running by mid March. It is unheated but will have an anti fogging cover on it giving a couple of degrees frost protection.

Realisticaly, when will it be safe to start planting tomatoes in it. Is April too early or should I wait until May?

Hi Piglet,
Tomatoes technically should never be allowed to be subjected to less than 10C and unless you have heating in your new Polytunnel it is probably going to be May before there is sufficient heat.
I know a lot of people grow Toms at a lower temerature but they run the risk of truss variations.
I read a commercial report about Gardeners Deleight about the difference in sizes of truss and the size and amount of the crop and the person who had written the report maintained that grown at a too low temperature and grown at the right temterature you would think that you were dealing with two different varieties. Gardeners Deleight is not supposed to be a Cherry Variety but if grown too low a temp they produce enormous trusses with what look like Cherry toms but do not attain the sweetness.
Grown at the right temp there are about 8/9 per truss and attain some size and also sweetness.

Thanks John

Know v. little about polytunnels. Tell me, what sort of heaters do you use in them if you want to heat them????

If you must heat them anything appropriate to a glazed greenhouse, but it's better to treat them as a different way of growing things more akin to garden frames except you can work in there at any time. Remember that basically they are difficult to ventilate properly at all times which means that any flame heating may aggravate humidity problems.For propogation a smaller enclosure gives a more economical way of heating, then maybe move the plants into the polytunnel as a preliminary to growing outside.For crops kept inside you gain an approximate 6 weeks extra on the growing season and some protection from the elements and pest and diseases. Get Bernard Salt's book Growing under Plastic if you can afford it.

All very interesting. We are hoping to move house in the summer and intend to find somewhere that's got a big enough garden for a polytunnel. So the book might be a good investment.

HI Folks
Is there any difference in in raising young plants in an unheated greenhouse and an unheated polytunnel? Help Please
Thanks
BAL

My toms went in my tunnel last year may 1st and was picking the first Sungolds on july 6th.These went in with no extra protection and no heating so you should be ok if in doubt drape some fleece over hoops.

Darren
Thanks. Did you plant your sungold in a cold greehose or cold polytunnel?
Bal

Cold polytunnel .I think i was pushing it a bit as the following week we experienced a lot of nor/noreast wind so i had to be vigilant with the ventilation as the day temperature one day was 84degs with night temp dropping to 4 degs .This year the tunnel is being used as a big giant cloche with doors and a lot more veg instead of toms and peppers are to be grown in it.

Sorry Darren - I can beat that, but only with heat early on. I sowed seed in a heated propagator at the end of January, planted out in disposable pots (a la Poundland) early March and set out in tunnels at Easter. First tomatoes middle/late June. Last tomatoes last week of November.

Grew Sungold, Sunbaby, Sicillian cherry tomatoes, Sicillian cooking tomatoes, Gardener's Delight, Beef Tomatoes, Moneymaker, plus several other heritage species. 122 plants in all in one tunnel.

Plan to extend range this year, and posssibly number - if only to make me the most popular member of staff at work. However - the real winner was home grown cucumbers in my other (unheated) tunnel - I could have retired for the season on the demand for these, once tasted. Pity I gave them away??!!

As for Bernard Salt's book - it's still the only definitive bible on tunnel tents as far as I'm concerned.

The other thing about tunnels is to let them find their own 'biological' infrastructure. Early on each year they look as though they are going to be overrun by aphids, mosquitoes, and other things, during March. If you leave them alone, and remember to keep the doors open during the day, you will attract frogs, toads and other creatures who will create the balance you're looking for. No sprays required.