What's the lowest temperature toms can stand?

[Aberdeenplotter]

(It's the thought that counts... Boom boom )

Indeedie. I'm not too bad with figures myself and love a bit of number crunching but I'm a big believer in technology. I'm also a big believer in being taught to do things by hand/head before employing technology though.

[Alison]

Haven't sown mine yet as I haven't got the space to keep them inside if I do sow this early. Most of mine never go outside proper and migrate from the window ledge to the greenhouse in early May, ready to be planted in the border by the end of the month. I find that I get great crops off this and the only ones I sow earlier will be some basket ones which will go in in a few weeks time (mid Marchish). At the moment I think it's too cold outside for most things and the only thing I have outside (which was sown this year) is some broad beans which are being hardened off.

[King Carrot]

How much fruit do you usually get? I've never weighed mine, but I don't think I get a lot of fruit (unheated gh, toms put in early May).

There is considerable evidence that night temperature is the critical factor in setting tomato fruit, the optimal range being 59° to 68°F [15c - 20c]. With night temperatures much below or above this critical range, fruiting is reduced or absent. Low temperatures reduce the production and viability of pollen. source: doh, lost it

The early variety was my own F4 saved seed from the Latah Vine breeding project from Real Seeds started from seed on 9th March and transplanted into the cold greenhouse on 24th April. The starting date of mid March follows the advice in Terry Marshall’s “Tomatoes” book for a cold greenhouse crop and gives a pollination time of early May. We were eating the first odd ripe tomato by mid July.

I thought one effect of temperatures less than 10C on the first trusses was to make them split and carry a larger number of smaller fruit, (certainly happened to me before with Garderners Delight in previous years) and the first trusses did split with the Latah Vine as can be seen in the close up. We do usually get good daytime temperatures (mid teens - 20 C ish) during May with lots of sun so it is possible any heat held in the greenhouse soil might keep the temperature up at night. It's also worth considering root temperature as well, as tomato roots will stop growing below a certain temperature. I would think a tomato in a greenhouse bed compared to one in a pot in a paved greenhouse would have less root temperature fluctuation in cold ambient temps.

These aren’t particularly early tomatoes compared to growers in warmer climates but for the fact they’re vines, the starting date and the fact they’ve been grown where I live in the cool and damp, I’m more than pleased with the results compared to my earlier years. I’ve started the Latah Vine a month earlier this year so we’ll see what happens, I’ll look to plant them out in the greenhouse in early April all going to plan and I'll be aiming to keep the temperature above 5C during cooler nights.

April 29th



July 4th



July 25th


close up crop from above showing first trusses

[King Carrot]

But that had nothing to do with the cold
He had basically starved them, made them think they were dying so they fruited more quickly

Just using this as an example of healthy plants possibly not being the best for fruit production. A certain amount of cold stresses plants as well as a certain amount of drought - too much of either will kill them.

[poly]

I remember reading a discussion about Cold Treatment for tomatoes last year, I think it was on another forum, but I found this Starting tomato seed which gives the details and may be of interest.

[Sylvan]

Thanks poly. That first tip is very interesting. Looks as though I've accidentally been doing the right thing for them

(PS: I've pm'd you)

[Sylvan]

Impressive tomato jungle KC.

I seem to remember my first trusses splitting. I thought it was normal

[Kristen]

I remember reading a discussion about Cold Treatment for tomatoes last year, I think it was on another forum, but I found this Starting tomato seed which gives the details and may be of interest.

Interesting (Although "cold" is 10C minimum )

I have considered a number of things, over the years, to a) get the first truss to occur lower down the plant (and probably sooner, as a result) and b) to reduce the inter-truss interval. Both of these were to try to get an extra truss on the plant before it hit the greenhouse roof! Taking cuttings from "elbows" of the Tomato plants gave new plants that had their first truss earlier on the plant (but that may just have been that there was more light available by the time the cuttings were maturing)

In the last few years I haven changed tack and now think this, although interesting, was a distraction!

By the end of the season I will have lost interest in pinching out side shoots and stopping the plants. They start to grow a bit wild at the top, and even though I start early and try to maximise my crop I don't really have a problem with the Tomato crop finishing BEFORE the end of the season. IN past seasons I have layered the Tomato plants (as commercial growers do) to extend the season - I don't think that achieved anything [in a domestic greenhouse] that just leaving them be would not also have achieved.

What I have done is to lower the beds in the greenhouse, and I don't use raised beds / pots / growing bags etc which might reduce the cropping height, so my crop has the maximum growing height possible in my greenhouse

So I'm not sure that making stockier plants (which seems to me like a good idea) is really going to make a lot of difference. An extra truss to the eves would be nice, but not really relevant if you would have squeezed it in anyway.

I'm growing my seedlings under extra light (from grow lights) this year. My guess is that that will make them stockier, and bring them on sooner, but its too early for me to be able to tell (I suppose I should take a couple of plants out as a "control" to compare later on ...)

[King Carrot]

Interesting (Although "cold" is 10C minimum )

I'm through the looking glass on that

[wellie]

I just love Terry Marshall.... he's what a tomato is to him, as is a loaf of bread to Paul Hollywood, and I have books by both of them.
And if I'm going to prove a loaf, or grow a tomato plant to provide what I'm proposing to eat by growing, proving or kneading, I'd be loathed to put myself through the 'dodgy end of the first stage' and then try and cock it up massively in the second stage on purpose? Why shoot yourself in the foot if you don't have to?

If you've bothered to bring that plant into the world to feed you, why not be nice to it, eh?!

[King Carrot]

I just love Terry Marshall.... he's what a tomato is to him, as is a loaf of bread to Paul Hollywood, and I have books by both of them.
And if I'm going to prove a loaf, or grow a tomato plant to provide what I'm proposing to eat by growing, proving or kneading, I'd be loathed to put myself through the 'dodgy end of the first stage' and then try and cock it up massively in the second stage on purpose? Why shoot yourself in the foot if you don't have to?

If you've bothered to bring that plant into the world to feed you, why not be nice to it, eh?!

I’m on a bit of a guilt trip now after placing my baby toms in an ever so slightly frosted glazed, tent greenhouse – almost sounds good enough to eat

I did wait for the sun to come over the hill and warm it a bit first though

You wouldn't beleive the time and trouble I lavish on them in the way of a single room each and fully organic nutritrious food - once they're a bit older of course, right now they're getting near their first seaweed drink.