Maf,

It is possible that the tomatoes themselves are also more resistant to cold temps. After all, all flower and fruit parts are simply modified shoots and leaves.

[url]http://www.beyondwilber.ca/about/plantmorphology/plant_morphology.html[/url]

[QUOTE=maf;312852]Interesting project, Dar I wish you the best success.

For those who are hoping this might extend the season in the fall, please be aware that even if the vine could handle 22F, the tomatoes on the vines would be spoiled by a hard freeze.[/QUOTE]

That's not an issue here. The issue is having 90 degree weather and a cold front comes along and drops the temp to 30-31 degrees just barely for long enough to kill your tomatoes, then the temp climbs back up into the 80's for weeks after. It is a real pain being right on the border of the climate zone between warm all year, but on a flat plain that releases heat so fast and allows a cold wind to chill things almost instantly. The air is typically so dry there is no humidity to hold the heat. Just a degree or two of cold resistance would make a HUGE difference.

The same type of thing happens in spring too. Usually not quite as bad due to spring rains adding moisture but still happens. You could be in shirt sleaves for weeks and even spot the rare bikini top now and then, then here comes the late cold front out of the blue killing everything, then right back to warm weather again.

If I didn't have to worry about the odd cold front, I could easily plant February 1st. As it is now I typically plan on March 1st and cross my fingers. (and have some plastic ready at a moments notice) Most people even wait longer just in case.

Problem is if you wait till it is totally safe you then need worry about the dreaded heat wave in summer that hits just about the exact time your tomatoes should be at their peak setting fruit. Top it all off with fighting the swarms of mice gophers rats squirrels and even insects that don't normally even like green tomatoes, but eat a bite or two out of each one just for the moisture......:?:

So you are basically d'd if you do, and d'd if you don't.

[QUOTE=Fred Hempel;312857]Maf,

It is possible that the tomatoes themselves are also more resistant to cold temps. After all, all flower and fruit parts are simply modified shoots and leaves.[/QUOTE]

Very true Fred, but the tomato fruit is thin skinned and watery which is not the ideal design for surviving a hard freeze. I will accept that the fruits of such a plant may be slightly more cold tolerant than regular tomatoes, but I think it is unrealistic to extrapolate the 22F from the young plants in the spring and to assume the fruits could endure similar temps.

What other types of fruit can survive the freeze/thaw cycle and carry on growing? I don't know of any soft fruit that can tolerate frost. My experience of fruits that can survive frost is that they are leathery, dry, tough, small berries, mostly not regarded as a food source by humans.

Very true. But we can dream...

and we can call it the super duper yooper mater




or something like that



keith

I would also be interested in helping with a growout. We often have snow and nighttime temps in the 20s in May and sometimes into early June. I realize that I would need to protect them from the snow, but if some combination of Walls O' Water and/or protective cloths might work. It's intriguing and definitely worth exploring!

Cool! (pun intended) But by the time it gets to be 22 degrees I am about tomatoed out for the year. It takes a couple of months to get recharged for the next growing season. But the project sounds really interesting. Good Luck.

Tomatoed out? Heresy!

When I read that...I thought the very same thing! Heresy!!

Moderators,

Please place Paul on double-secret probation.

Actually there are a plenty Russian amateur and commercial tomato varieties to survive at -7C (19,4F) and even lower at -14C (7F).

The most popular (in Russia) extreme cold tolerant amateur tomato varieties were bred by Saraev P. from Russian town Orenburg: Stepnyak, О-33, I-3 or Iyunskiy-3, Gruntovyi, Limonchik, Sibiryak, Orenburzhets, Kemerovets, Spiridonovskiy etc.

I've tried Spiridonovskiy, Kemerovets and I-3. They were really cold tolerant at least at about 0C.

More reading for Russian speaking enthusiasts abour Saraev tomato varieites: [URL="http://sadoved.com/3798-saraevskie-tomaty-zamechatelnoe-nasledie.html"]http://sadoved.com/3798-saraevskie-tomaty-zamechatelnoe-nasledie.html[/URL]

Mea Culpa! Usually from hard freeze (late October) to seed starting (the first week of March) I rested, researched, dreamed, planned and purchased. Now that I teach a class for the local community college and for a 4-H group on starting plants from seeds, my down time is about 30 days. This year all my tomatoing has ended this week. In order to have planting sized tomatoes ready for the February classes it begins again in a couple of weeks. So take a deep breath along with me. Just think what it would be like if I tried to do the really hard stuff like breed new varieties. Heretical? Yep, I guess so. Sorry.

Andrey, do you have access to seed of some of the cold tolerant varieties? If so, please PM me if you would be willing to ship me a few to trial.

Thanks,

DarJones

Andrey, is the 'Gruntovyi' you mention different from 'Gruntovyi Gribovskiy'? I have seeds for that one and it is supposed to have good cold tolerance; just wondering if it is the same?

Robot translated text from Andrey's link ([URL="http://sadoved.com/3798-saraevskie-tomaty-zamechatelnoe-nasledie.html"]http://sadoved.com/3798-saraevskie-tomaty-zamechatelnoe-nasledie.html[/URL] :
[QUOTE]Sarajevo tomatoes: a remarkable legacy


Spring frosts in many areas there are up to June, and often early planted tomato seedlings die. Help avoid this kind of Orenburg breeder Paul Sarajevo, which for decades led the work on breeding tomatoes for resistance to cold.
The main thing - the wind and moisture
Cold-resistant varieties can be planted seedlings much earlier than usual and, respectively, before a crop. And the use of film shelters accelerates ripening and significantly increases productivity. However, speaking of Sarajevo resistance varieties to frost, you should know that this is only possible at low humidity (dry air) and windless weather.
For a long time scientists advised growers evening and night watering as effective against frost. Similar recommendations are found in the literature and now, but this is false. Everyone knows that a man in wet clothes is much colder, especially in windy conditions.
Evaporation causes cooling fluid, and along with it - the cooling of the body. Hypothermia can be even at zero temperature, if increased humidity. Wet surface gives four times more heat than dry.
Gardeners necessarily consider when early spring transplanting two main factors: humidity and wind.
After planting, water the seedlings need a time, and not to do this until there is no danger of frost.
In the period after transplanting until it settle down, the plants decreased resistance to cold, so the seedlings should be planted with minimal damage to the root system (eg pots) that the period of survival was minimal. When growing seedlings should be periodically from the moment of its emergence exposure nighttime freezing temperatures, ranging from a few minutes hardening and increasing it to a few hours. When planting in the ground need to protect seedlings from wind any available material.
Most hardy varieties
Spiridonovskaya. Undersized, standard, precocious. The fruits are small, up to 60 g, red, suitable for canning. From germination to early maturation under favorable conditions, is 80-90 days. Resistance to low temperatures was confirmed by the Institute of Biology, Karelian Branch of the RAS. When tested in young seedlings survived four frozen to -14 °.
Orenburzhets. Undersized, standard. Red fruits, weighing 80-100 g, good taste, universal purpose. Endured three consecutive freeze: -5 °, -7 °, -10 °.
Kemerovets. Undersized. Pink fruits weighing up to 100 g, high commodity and taste, universal purpose. Withstood freezing -7 °, -10 °, -13 °.
0-33. Srednerosloe. The fruits are large, up to 200 g, flat-round, red. Beginning maturity - Mid-July, the yield per bush - more than 6 kg. When tested survived two freezing and one -9 ° -7 °.
Stepniak 50. Srednerosloe. Red fruits, weighing 30-50 g, rounded, smooth, multi-purpose. Is resistant to temperature variations. Went through five freezing to -10 °.
I-3. Average height, very early, in good years the fruits ripen in late June. High-yielding. Fruits are flat-round, red, weighing 100-200 g when tested went through five frost from -6 ° to -11
Siberian. Srednerosloe. Fruits are flat-round, red, large, fleshy, high taste. Variety is very crop. When tested withstood seven frozen to -10 °.
Lemon. Tall, late-maturing. The fruit shape and color to its name, weighing 70-80 g, hang huge brushes, very harvest. The fruits are fleshy, well-kept, suitable for canning. Through three freeze to -10 °.
M-16. Tall, late-maturing. Fruits are very beautiful shape, good presentation. Weighing 200-300 g, fleshy, good taste, well kept. Tests: one frost -3 °, two - on -10 °.
Tomato F1RR. Fruits bright red, flat-round, multi-chamber. The pulp is fleshy and juicy, with a high sugar content, has amazing taste. With proper care and rationing of the ovaries in the brush can grow fruits record up to 2 kg! The plant is vigorous, indeterminate. Fruits ripen 130-140 days. Juice of them get a very thick, well and quickly boil down to the consistency of a paste, and one fruit salad can be prepared for the whole family.
MA Litvinov, p. Novoaleksandrovka Orenburg region. [/QUOTE]