Cold tolerant tomatoes, right down Joseph's alley.

[Joseph Lofthouse]

My daddy reported 30F the other night at his house a couple blocks from my garden where the frost/cold tolerant trial is taking place. That's at standard 5 foot height, and the night was crystal clear, so add another 8 degrees or so radiant cooling to the leaves near ground level. The frost was the heaviest that we have had in 4 years. I base that on this being the first time that Joseph's Frosty sweet corn has frozen since I started growing it. The corn froze completely down to about 3/4" above ground level. It's fine and will recover.

I ranked the tomatoes today... It was close to total devastation. I deleted anything from the list that I classified as dead beyond recovery. If something is still on this list it may have enough life left in it to recover. One * indicates near complete defoliation but the stem still seems viable and there was some bit of green leaf left. ** means there was heavy damage but still a bit of green on a few leaves. ***** would have indicated no visible damage. I replanted, and put the replacements about 6" away from the dead/damaged plants so perhaps some of them will recover.

Code	Name	Frost Tolerance Score	Notes
F6	Matina	*	-
F11	E6	*
L4	Landrace	*
L6	Landrace	**
L7	Landrace	*
L8	Landrace	**
L10	Landrace	*
L12	Landrace	****	This plant is extremely small. It is not as tall as the 3/4" freeze line on the corn. There was a tiny bit of damage that might be due to a bug or bruising, so I couldn't give it a perfect freeze tolerance score.
L13	LA 3969	*

.

[Joseph Lofthouse]

I scored the tomatoes for the frost/cold tolerant trial today... Nothing cold about the weather this year other than intense radiant cooling at night. Oh well. I'm not listing detailed notes about them this week. There's a lot of really nice looking tomatoes.

I noticed flower buds starting to form on: Matina, Jagodka, E6, and Joseph's earliest 2013. They were also precocious last year. The tomatoes that were (re)planted after the frost are doing much better than the ones that were froze and are trying to recover.

I lost tract of how many Jagodka I planted... More than 100. Hehehe.

On the flat of mixed seedlings that I allowed to stay outside during our last cold weather (May 13th), about 5% succumbed immediately to the cold, and about another 10% developed symptoms like yellowing or twisted leaves. I culled the damaged plants. I don't suppose I'll do anything with the survivors. I've already got all the tomatoes I want. I would have liked a somewhat harder frost.

[Joseph Lofthouse]

Thank you FusionPower!!!

These tomatoes, ~100 pounds, are mostly descended from last year's frost/cold tolerant trial. They are heavily represented by Matina and Jagodka. My standard tomato, DX 52-12, is not anywhere near being ripe. The Brandywines might get around to setting fruit one of these days... Alas, too late. Frost could be here in 2 to 3 weeks.

I collected the earliest saladette sized strongly determinate plants into a population. I combined the various lines with like-phenotype into the same seed lot. And I collected the earliest determinate slicers into a population. They were a week behind the saladettes.

There is one odd-ball plant, an early indeterminate with medium (for me) fruits that doesn't fit into either group, so I may save it separate. It has been a favorite for years because it produces very early and keeps putting out until killed by frost.

I also saved a batch of seed that I am calling "Best of Jagodka" which produced more heavily or had larger fruits. And I saved a few Jagodka as fruit-to-packet.

I saved a batch of seed that I am calling "Best of Matina" because the fruits are much larger than the rest of the patch. Don't know if the difference is due to slight differences in environment, or slight variation within the cultivar, or hybridization, but it seems worth the effort to keep them separate.

The corn is my way of sneaking in an extra photo of Astronomy Domine sweet corn into the forum.

Alright... Off to find the canning kettles.

[DarJones]

Note that Joseph did all the work, so we should call this Joseph's Early Grex tomatoes. Without his efforts to trial several very early varieties last year, he would still be waiting on ripe tomatoes.

Joseph, we still need to cross LA3969 to Jagodka and see if there is a favorable segregation of the genes. I expect we will find something useful along the way.

[DebTheFarmer]

If you want/need a similar climate to trial those tomatoes next year I can help you out

[Joseph Lofthouse]

DebTheFarmer: Many of the ancestors of my tomatoes come to me via Dan McMurray of Creston BC. So I bet they'd feel right at home at your place.

[Joseph Lofthouse]

I lost about 35 plants to last night's cold weather out of about 150 that I had exposed to a frost tolerance test. 32-35F depending on which thermometer I believe, plus mild radiant cooling.

Matina, Jagodka, and Early Landrace fared poorly. (To be expected I suppose since Early Landrace was mostly Matina and Jagodka.)

Tastiheart, LA3969, and DX52-12 did fine.

About 10-20% of the plants wilted in Landrace Slicer, Landrace 2012, current tomatoes.

Another cold snap and or snow expected in 2 days.

[Joseph Lofthouse]

This flat of tomatoes survived two days of snow. The flat had already been challenged previously by about a week's worth of near freezing temperatures and radiant cooling. No additional plants succumbed to the snow. This is way more survivors than I had hoped for... I'll continue challenging them with cold if the opportunity presents itself. At least I have identified some lines that have very little frost tolerance.

[DarJones]

I started planting tomatoes today with the first row of 48 plants. This row will be a Sunlucky line derived from a cross of Little Lucky X Sungold and selected for Little Lucky flavor combined with Sungold sweetness. It is at the F5 and produced some exceptionally good tomatoes last year. I also have a few breeding lines for cold tolerant breeding. LA3969 and Tastiheart are going to be very good friends this year. I have Piennolo del Vesuvio X LA0417 and a few other similar crosses to grow out and select for disease tolerance. All told, I hope to grow about 380 tomato plants this year with some for seed and others for breeding work.

[Joseph Lofthouse]

Apr 30, 2015 18:56:21 GMT -5 DarJones said:

I also have a few breeding lines for cold tolerant breeding. LA3969 and Tastiheart are going to be very good friends this year.

I'm growing both of those this year. They are a bit long-season for my garden. So perhaps I'll use them as pollen donors to something shorter-season. Both of them survived the cold tolerance test this year.

I took clumps of the survivors from that flat and planted them into a colder field about a week ago. That is 6 weeks earlier than I usually put tomatoes into the field, and 4 weeks earlier than average last frost date. Since they were planted out, low temperatures have been around 38F to 40F at night with radiant cooling some nights. I culled a few plants that showed damage, but most looked fine.

[Joseph Lofthouse]

I guess this is where I say, "Oh, Duh."!

Some of the tomatoes from this year's frost tolerance test are currently producing ripe fruit. I planted them into the field on about April 23rd. (Normally I plant out tomatoes approximately June 5th.) I planted them into the field after they had already been culled by radiant cooling freezes, and two days of snow laying on them. Once in the field I paid attention to them and culled those that showed (the most) frost/cold damage.

The first to ripen fruit was an F3/F4 plant descended from SunGold. Since we suspect that SunGold is descended from Solanum habrochaites, and we know that S. habrochaites has quite a bit of cold tolerance, this is where I get to say, "Oh, Duh." I've already been saving a bunch of SunGold and SunSugar seeds to screen for interesting flower types next year. Now it looks like I aught to be growing them to screen for frost tolerance too!

There were two of the SunGold descended plants in this year's cold test that I didn't cull. One has about 1 ounce fruits, and the other about 0.4 ounce fruits. They weren't flowering when I checked on them yesterday. I am also growing 6 plants of this line in my production patch.

[Joseph Lofthouse]

From last year's frost tolerance test that was planted into the field on about April 23rd, I collected three types of seed: Current tomatoes, Descended from Sungold, and slicing tomatoes.

I planted those into a flat today, along with other varieties. I planted 36 varieties in total. The planting included wild tomatoes and related species: Solanum Habrochaites, Solanum Pennellii, Solanum Peruvianum, Solanum corneliomuleri, Solanum Cheesmanii, Aunt Molly's ground cherry, tomatillo, Physalis peruviana, LA3969, and crosses between wild tomatoes and domestic tomatoes. Included in the planting were segregating populations of crosses between tomatoes that have scored well in my garden for frost or cold tolerance. Other varieties that have shown frost tolerance were included, for example Casey6400CO sent me two varieties that survived 5 days of frost in his garden. (Later Edit: I lost my Tastiheart seed in the move last summer, but some of it was probably included in the landrace seed collection, so it's likely to show up again. I found a packet of Tastiheart seed, but it didn't get included in this trial.)

My greenhouse is still freezing at night. So I put the flat of tomatoes on the floor of the greenhouse. I'm intending to pay attention to which varieties germinate first. Later on, I intend to subject the young plants to frost intentionally, and to plant them out way-too-early, to see what survives. In my ideal world, I'd like about an 80% to 90% death rate...

[taihaku]

Feb 22, 2016 19:26:46 GMT -5 Joseph Lofthouse said:

From last year's frost tolerance test that was planted into the field on about April 23rd, I collected three types of seed: Current tomatoes, Descended from Sungold, and slicing tomatoes.

I planted those into a flat today, along with other varieties. I planted 36 varieties in total. The planting included wild tomatoes and related species: Solanum Habrochaites, Solanum Pennellii, Solanum Peruvianum, Solanum corneliomuleri, Solanum Cheesmanii, Aunt Molly's ground cherry, tomatillo, Physalis peruviana, LA3969, and crosses between wild tomatoes and domestic tomatoes. Included in the planting were segregating populations of crosses between tomatoes that have scored well in my garden for frost or cold tolerance. Other varieties that have shown frost tolerance were included, for example Casey6400CO sent me two varieties that survived 5 days of frost in his garden. I lost my Tastiheart seed in the move last summer, but some of it was probably included in the landrace seed collection, so it's likely to show up again.

My greenhouse is still freezing at night. So I put the flat of tomatoes on the floor of the greenhouse. I'm intending to pay attention to which varieties germinate first. Later on, I intend to subject the young plants to frost intentionally, and to plant them out way-too-early, to see what survives. In my ideal world, I'd like about an 80% to 90% death rate...

a few years of this kind of selection pressure and you'll be dealing with how to crop feral volunteer toms to go with your tomatillos.....

[keen101 (Biolumo / Andrew B.)]

I was reading about sweet potato shivering in the fridge and the article also mentioned tomatoes and bananas and how they rot faster at cooler temperatures because they are tropical plants. I'm curious to know if any of the frost tolerant lines also have longer ability to store [fruit] at cooler temperatures than your average tomato? It should be easy to comparisons, just plop two tomatoes in a fridge side by side or in a cold storage room.

[Joseph Lofthouse]

2016-03-05: The first seeds to germinate in this year's cold frost tolerance trial are: Sun-2, Sun-4, and PI 128650 (S. peruvianum). The Sun varieties are descended from Sungold. Between the cold tolerance that the Sungold descendants showed last year, and the exerted stigmas in the population, it's moved higher up on my priority list for crossing with other varieties.