Help needed yet again please (re toms and peppers)

**muddled** · 08-12-2014, 10:49 PM

Oh no!
Don't be sad!
I don't know anything about polytunnels but I do know that everybody here has had seedlings die en masse at some point. You'll figure out why and sow more and it will be fine!

I wonder, what are the light levels at this time of year where you are?
I know that chillis are affected by day length as much as temperature....could that be it?

And cukes are very prone to damping off. Cinnamon is s'posed to help but I have had success by putting the seed on top of the compost and then topping with an inch of vermiculite (instead of more compost).

Don't be disheartened....we'll get to the bottom of it xx

**veggiechicken** · 08-12-2014, 11:08 PM

Sounds like shock - such wide variation in temperature. You'll need to cool the tunnel down if temps are that extreme.
Your tomato looks like its flagging from the heat and may well recover.
I'm no expert, especially with polytunnels, just thinking about greenhouses. Don't despair, chalk it up to experience and sow some more.

**Zelenina** · 09-12-2014, 12:22 AM

Commercial greenhouses in Almeria use various kinds of shade screens, energy saving screens and solar reflection screens to control the temperature and light levels.

Screens

I don't suppose you'll be wanting anything as high tech as that, but maybe you can find something similar for use by gardeners. Or if any of your neighbours have garden-sized polytunnels you could find out how they do it.

**Zelenina** · 09-12-2014, 12:33 AM

Maybe some shade netting over the tunnel like this would do the trick.

Net Polytunnel Covers - Buy by the Metre - Premier Polytunnels

It would shade it during the day and keep some heat in at night. I should think low light levels in winter wouldn't be such a big problem in southern Spain as they are in the UK, which is quite a lot further north.

**sparrow100** · 09-12-2014, 06:23 AM

Don't tomatoes need minimum nighttime temps of 10C to grow? I don't know where I picked that up, but it's lodged in my head. Cukes are similarly in need of more warmth at night or they will die on you.

**Bacchus** · 09-12-2014, 10:32 AM

Originally posted by sparrow100 View Post

Don't tomatoes need minimum nighttime temps of 10C to grow? I don't know where I picked that up, but it's lodged in my head. Cukes are similarly in need of more warmth at night or they will die on you.

That was the figure I had in my head for most peppers.

**Lisasbolt** · 09-12-2014, 10:47 AM

Thanks everyone.

I guess a lot of it will be trial and error, you have to learn someway

Normally night time temps are about 8-10 outside so thought inside the tunnel it would be fine.

In several seasons i might nail it (then move back to England

)

**Kristen** · 09-12-2014, 10:57 AM

Tomatoes, Cucumbers, Peppers, Melons, Aubergines all need a minimum of 10C. I'm sure if they get 9C or 8C for an hour, just before sunrise, that will probably be fine, but once they get below 10C for any length of time they "stall" and it takes prolonged warmth to get them going again. (Tomato leaves turn Purple, I've forgotten what the chemistry is but its something like them not being able to assimilate Phosphate, which then mucks up the plant's ability to grow normally, hence they "stall" as a survival mechanism until temperatures warm up again). Dunno if a low-ish night temperature, followed by hot days, will fix the problem as we don't normally get that here in early Spring; whereas in other countries plants survive lower temperatures because they then get nice hot days, so that might work for you allowing lower night time temperatures. But ... it might be best to wait until you are sure you can maintain 10C at night before starting to grow crops that are sensitive to a 10C minimum temperature (or provide some heat? it won't take a lot to maintain 10C if the temperature will only fall a couple of degrees below that)

**Scarlet** · 09-12-2014, 02:39 PM

What do other growers around you grow now? If your tom plants were established they would be able to tolerate some cooler temps although they would slow down. Do they start off plants now, or are they growing on mature plants? I grow in a GH, young chilli plants (IMO) are best in temps 15 and above to grow well, older plants can tolerate temperature that are cooler than this.

As for ventilation, befor I had my auto openers I made sure I was up early to open the doors, windows and vents. You need to get a system in place for ventilation and shading.

**kathyd** · 09-12-2014, 03:21 PM

Debris netting on hoops during the day will help to shade and still allow air to circulate, and add fleece at night to protect a wee bit from the cold. Water on the paths during the heat of the day is said to help cool things down but I've not tried it. My polytunnel is 30ft long, and I have double doors at both ends which are open most of the time (even during the day in winter), plus a 'skirt' along the south side - you can roll the bottom half of the polythene up when it's hot and there's netting underneath which allows more air through. But I agree with the others, find out what other people are doing nearby, and pass on any handy tips to us won't you!

**Zelenina** · 09-12-2014, 07:17 PM

Almeria or Costa del Polythene is the polytunnel capital of Europe, or maybe the world. It's where a lot of the winter toms and cukes and peppers and beans in our supermarkets come from, so it's certainly possible to grow them there.

"The crops are grown continuously from October to July, with production peaks in December-January when tomato, cucumber, green beans, and pepper are harvested, and then again in May-June when melons are in season."

Costa del Polythene

But the methods used by commercial growers may not be practical for you as an amateur, Lisa. And it is difficult getting used to growing stuff in a different climate, as I'm finding here in Slovakia. I've had my share of failures too. So keep on trying and experimenting. Don't get let it get you down

**Scarlet** · 09-12-2014, 07:29 PM

Originally posted by Zelenina View Post

"The crops are grown continuously from October to July, with production peaks in December-January when tomato, cucumber, green beans, and pepper are harvested, D

That implies that plants are well established before the cooler winter nights. Mature toms and chillies will stand cooler temperatures but seedlings won't.
Lisa, have you looked at a sowing calendar guide for your area - growing all year round doesn't mean that seeds can be sown during the winter. Although you will have a very long growing season, I'd still be tempted to say don't start off your tom seeds until jan and keep them indoors until the nighttime temps don't drop below 10.

**Penellype** · 09-12-2014, 08:17 PM

Agree wholeheartedly with the comments about shading. You need to get the daytime temperature down.

I start off my Sungold tomatoes in the house and put them out in polythene growhouses in May, when they start to get too tall for the windowsills. Here are extracts from my notes in the cold spring of 2013:
10/5 remaining 4 plants getting too straggly for their small pots. 2 of them potted up into 2 and 2.5 litre pots and put on sitting room windowsill. Other 2 planted out into soil near back door, with the top part of the growhouse over them and covered with a plastic sheet weighted down with bricks. Plants are still small (6 leaves) and I am prepared to lose them.
16/5 the 2 plants outside are surviving despite night temps of around 3 degrees. However there are ominous dark patches on the stems, although not on the leaves - they may be simply cold.
4/6 The 2 plants that were planted out first are only about half the size of the others and still looking poorly, with stems that have gone a bit brown.
18/7 the 2 plants put outside first have recovered but are slightly behind the ones in the cold frame. [Note - These were the 2 plants mentioned earlier, put in pots on the windowsill, and were planted out in the cold frame on 4/6 after the worst of the cold]

I think this illustrates that tomato plants can survive colder temperatures than 10 degrees, although it may depend on the variety. I find Sungold is fairly hardy as tomatoes go. I do think though, looking at the size of your plants, that they would benefit from being grown on in a warmer environment (eg a windowsill indoors) until they have grown a bit.

(Yes, I do try to keep this sort of notes for everything I grow - sometimes I find them useful!)

**Kristen** · 10-12-2014, 12:53 AM

Originally posted by Penellype View Post

tomato plants can survive colder temperatures than 10 degrees

Indeed they can, but in my experience they then "stall" and it takes a fair bit of heat to get them going again, so it represents a delay in cropping. I think this matters most to folk that start them off early, with the aim of getting earlier cropping. Last year several of my mates decided the faff of starting them early wasn't worth it, and waited and sowed later. I sowed in February, grew mine heated and with supplementary lighting, and my first harvest was maybe a couple of weeks ahead of my chums - almost certainly not worth it!

Important point others have made above is that this is an issue with young plants, as mature plants will suffer far less trauma from cold temperatures.

Pretty sure there was a "challenge" on here a few years ago to raise Tomatoes super early and without supplemental heat??

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Help needed yet again please (re toms and peppers)

Help needed yet again please (re toms and peppers)

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