Tomato variety for cool, frosty weather?

VermontCathy

Can anyone suggest a tomato variety that will thrive in cool weather and won't die at the first touch of frost?

I have grown varieties like Sub Arctic and Siberian and they do all right, but typically these "cool" tomatoes have been bred and selected to grow quickly in a short warm season, rather than growing and fruiting in cool-to-cold weather.

With so many of us living in cooler climates, I'm hoping someone here can help.

It may be that no one has bred for this trait. If not this could be a very interesting home gardening project!

LaurieLovesLearning

@VermontCathy I've never heard of one.

Torey

I can't grow tomatoes outside. Its just not warm enough most nights in the early part of the summer to set fruit as they need an overnight minimum of 10C (50F). So far we haven't had one night yet that has been above 10 at night. Then the overnight temps drop very quickly in late summer so the fruits don't ripen well. Our short warm season isn't long enough for proper flower and fruit development.

I have only had success in a greenhouse (and that is limited success) or patio type ones that grow in a more protected spot that gets warmth from the house.

So I would also be very interested if someone has heard of a variety that will set fruit in cold temperatures.

VermontCathy

I'm going to do some library/web research on this, and I'll come back and post a summary of what I learn.

I see no reason in principle why a tomato could not be bred to set fruit at 5-10 C/40-50 F. But the plant breeding work needed to do that may not have been done.

Cornelius

Another possibility is to grow one of your favorite varieties inside with a grow light. You can hand pollinate it with a paintbrush and it would live and produce for a few years!

VermontCathy

@Cornelius I don't have enough room in the house for that. I routinely grow spouts and shoots under a grow light all winter, and I started tomatoes from seed there early this year, but a full-sized tomato plant in the house isn't going to happen.

I have thought about trying Tumbling Tom in a pot, but haven't done it.

SuperC

This is a tough one, i am uncertain of which tomato/s can fruit in colder temps. @VermontCathy , have you had results on your research?

VermontCathy

@SuperC I have already learned a lot, but I'm not quite ready to write a detailed summary.

VermontCathy

Here are my tentative conclusions.

There are quite a few tomatoes that are claimed to be approriate for cool or cold conditions. However, as far as I can tell from brief Net research, none claim to survive a frost, and few claim to be able to set fruit in cool weather. (One site claims Glacier "may" survive a "light" frost.)

It is reported that "Cool nighttime temperatures interfere with the tomato plants' ability to convert sunlight into sugars through the process of photosynthesis. Low temperatures also reduce pollen production, resulting in fewer fruits or even fruit deformation. Cat-facing, which is puckers, scars and cracks on the blossom end of the fruit, occurs when nighttime temperatures drop below 60 F."

Days to fruiting among this group range from 42 days (Sub Arctic, some sources but other rate Sub Arctic at 60 days) to 78 days (Russian Red).

Glacier, Siberian, and New Yorker are claimed to set fruit in cool temperatures.

However, the temperature range quoted for Glacier is 50 F - 95 F, which doesn't help those looking to set fruit below 50 F. Other information sources say that blossom drop can occur below 55 F, so 50 F may be seen as "cool" compared with other tomatoes.

Siberian is more encouraging. It is extremely dwarfed with thick stems plant "is able to set fruit in very cool weather (reports of 38˚F)." It is reported as "suitable for containers and extreme climates."

I haven't found any specifics on New Yorker's temperature range or fruit set.

So of the existing varieties, Siberian and Glacier would be most likely to manage to set fruit at lower temps. I have grown Siberian once, though I wasn't pushing its temperature limits.

More in next posting...

VermontCathy

Joseph Lofthouse is developing a landrace of tomatoes for his own garden, and he recommends this approach. Although tomatoes tend to self-pollinate and inbreed, if you have a healthy pollinator population (especially bees) and plant the tomatoes close together and mixed up, you will get significant crossing.

There is a site, opensourceplantbreeding.org, that has a forum dedicated to tomato breeding. Several people there are working on tomatoes for frost tolerance, but there is a report that the gene for frost tolerance may be completely different from the gene that allows the plant to grow in cool conditions. The best variety would include both of these.

It was mentioned there that Jagodka, a variety from the Vavilov Institute of plant science in Russia, has "high ability to grow in cold weather" despite not being frost tolerant. However, it is "strongly determinate", so don't expect to keep cranking out tomatoes over a long season.

I am thinking that I could buy seeds to a dozen varieties of tomato, plant them together in several beds to encourage crossing, and select them over several generations for high tomato production in Vermont late in the fall season. Over time this should produce a landrace that is relatively tolerant of zone 4 cool conditions.

Unfortunately I have not found any sign that any existing tomato variety can handle frost and is happy growing and fruiting in temperatures that drop below 10 C / 50 F daily. No amount of crossing and selecting is going to change that unless a useful mutation occurs. The genetic material to do it doesn't appear to exist in cultivated tomatoes.

In the broader solanum family that includes wild tomatoes, there a few plants that are more cold-hardy and have potential to be cross-bred with tomatoes to make them more accepting of the cold. These include Solanum habrochaites, Solanum chilense, and others that don't produce tasty fruit, but could provide useful genes. S. chilense is reported to grow as high as 3900 m (12,800 ft) in Chile, which implies strong adaption to cold, dry weather. There are several of these wild plants in the so-called "Peruvianum complex."

Bottom line: the truly cold-tolerant tomato I am seeking doesn't exist today, and probably cannot be easily bred by crossing existing tomato varieties, but very likely could be bred by crossing cultivated tomatoes with wild ones, and there is a bit of work being done on this by amateurs.

Sheila

If you can source them Pollock tomatoes were developed by a gentleman from Houston, BC at about 3500 ft. He grew them in both a greenhouse and outdoors and they set fruit in cool weather and hot. He was working on a cold hardy variation but unfortunately passed away before he had grown more than a couple of plants. I grow the Pollocks on Vancouver Island which is notorious for cool summers with the occasional heat spike. They are a good plant as well for indoors - I have known people who grow them in a 5 gallon bucket and bring them in for the winter where they continue to bloom and produce throughout the winter when placed near a south facing window.

Torey

Thanks for this info @Sheila. I hadn't heard about this tomato before. Despite the fact that Houston is several hours north of me, it has the moderating influence of a large river and is zone 5a so a bit warmer than me.

Seeds of Diversity has a good article about Andy Pollock.

https://seeds.ca/d/?t=d36a71fd00003806

Here are two sources for seeds.

Annapolis Seeds in Nova Scotia. https://annapolisseeds.com/products/pollock-tomato

Salt Spring Seeds. https://www.saltspringseeds.com/products/pollock

This is an interesting site. This farm is not far from me (in Central BC) but in a better growing zone (5); we will get a frost before they do. She has listed every tomato variety she has grown over the years and gives a review of each one, including the Pollock. https://hillfarmnursery.com/tomato-long-list-1991-to-2013/

Sheila

@torey Andy actually lived up on Buck Flats about 30 minutes outside of Houston (lists as 4a/4b) and up the mountain. His zone was closer to 3a/3b as he was at a much higher altitude (I think it was around 3500 ft). He would plant a couple hundred tomatoes each year from his stock and mark the first 50 to sprout that he would keep. He selected for early sprouting, fast growth, small seed spaces with large seeds and especially for flavour. He spent close to 40 years developing his Pollock tomato from a Bonny Best sport he discovered in his Kamloops garden and then concentrated on the cold hardiness after he moved to Houston when he retired. He was a great friend and I miss him dearly.

His Pollock tomatoes have survived frosts here on the Island protected by just the plastic over the greenhouse on milder winters. The last couple they haven't made it but part of that has to do with the snow collapsing the entire greenhouse almost to the ground. But this year is a teardown and rebuild so we will reinforce for the darn wet snow!

judsoncarroll4

THis is all excellent info!

vickeym

Has anyone found the Pollock tomato seeds in the US? Been looking for about an hour and have not found a source yet.

Torey

I have looked for a US supplier as well @vickeym, also without success. Neither one of the seed companies I mentioned ships to the US. If you like, I can order some for you and then mail them to you.

vickeym

Will they let you mail them? Wasn't sure if that was allowed. Would be happy to pay you for them and the shipping.

VermontCathy

The US has some restrictions on mailing seeds depending on the destination state, but I don't think tomatoes have many restrictions.

Torey

There are all sorts of regulations for commercial sales of seeds between the US and Canada, however, I can't find any regulations on shipping a single package. Small lots sales of less than 50 packages (of less than 50 seeds each) require a small lot import permit.

Most seeds are allowed to be shipped unless they are on a prohibited list for each state but I can't find tomatoes on that list.

One package of seeds should be able to make it through the postal system.

Do you want them now @vickeym? Or do you want to wait until later in the year so you can have fresh seed from the fall crop?

VermontCathy

@torey Be sure to check state regulations too. Many of the rules are not at the federal US level. But I agree that one package of seeds from an individual to an individual is unlikely to be a problem.

vickeym

https://community.thegrownetwork.com/discussion/comment/914234#Comment_914234

Our season is short enough that we do not have a fall harvest, one and done unless you have a heated indoor space for them. I don't have that option...yet. lol

VermontCathy

@vickeym I think @torey meant that you might want to wait for her fall crop to produce fresh seeds.

Torey

@Sheila Where do you live on the Island? I have friends who have just purchased a place on the north Island. She is trying to convince me to come and do plant walks.

Merin Porter

https://community.thegrownetwork.com/discussion/comment/914159#Comment_914159

Thank you for doing all of this research and sharing it with us! I haven't heard of these before -- I have a pretty short growing season (110 days) and so far have just resorted to short-season tomatoes. I do get tomatoes for a month or two before the frost sets in, but it would be awesome to be able to have tomatoes after it gets a little cooler at night....

SuperC

@VermontCathy , thank you SO much for your research and results! :)

Martin Novotny

We have at least 2 varieties here in Europe that fit "colder climate" criteria - Washington Cherry and Glacier. Last year I have had quite a harvest in an area where temperature does not go above 68F in peak summer - thrive well in between 53 to 68F...

vickeym

https://community.thegrownetwork.com/discussion/comment/914425#Comment_914425

I will have to look into these as well. Thank you.

DozenElk

I live in the high country at an elevation of 8500 ft. Cold Climate tomatoes make a bush but no tomatoes outside in the garden. Summer nights are around 40 degrees F here. I also have a very short growing season. The only way I have been able to grow tomatoes is in a pots in the house. However, with no bees in the house to pollinate the blooms, I tickle each bloom with a kid's watercolor brush for pollination. What has worked best for me in the house is EARLY GIRL. I have to be careful of variety, because some make too much folage for my small tomato area. I have tried many kinds of tomatoes and I plant seeds. I wanted Heirloom tomatoes, so I could save the seed, but all the heirlooms I tried grew huge plants. EARLY GIRL lived thru 3 winters producing tomatoes, here in the house. I had no idea they could do that. Yes, I did prune them each spring.

VermontCathy

I'm still researching information for cool-climate tomatoes.

One interesting find is the "Soviet dwarfs". These are tomato varieties that were bred in Russia during the Soviet period, and some are likely reasonable cool-climate types.

Usually discussions of tomato plant size revolve around determinate vs. indeterminate.

Determinate tomato varieties grow to a moderate height, then stop growing and produce fruit all at once. They are adapted to produce tomatoes for canning sauce, salsa, and so forth, where you want a lot of fruit at the same time. But they won't keep producing fresh fruit for you over a long season.

Indeterminate tomato plants never stop growing, but keep getting taller and producing new stems that produce more fruit. So you get a little bit of fruit at a time over a longer season, but the plants are a pain to stake and support, and if you let them droop the stems can break or the fruit end up resting on the ground and rotting.

Dwarf tomatoes are indeterminate, but bred to remain fairly short even as they keep growing. I will be very interested to see how they do here. Tomato cages should be tall enough for most dwarfs, without needing to create a really tall staking system.

This year I am trying Uluru Ochre, Olena Ukraine, and Krainy Sever, all of which are Soviet dwarf tomatoes.

VermontCathy

@DozenElk If you are growing domestic tomatoes, you shouldn't need either bees or a brush to pollinate. Domestic tomatoes have been adapted to self-pollinate. In fact, it can be hard to produce deliberate crosses of domestic tomatoes, because the stigma will usually already be pollinated inside the flower before the flower even opens.

Any time you aren't getting fruit from tomato plants, the problem is probably not directly related to pollination. It could be related to cold destroying the pollen, cool weather preventing fruit set, or other issues.

(I emphasize "domestic" because self-pollination isn't true of the wild precursors to tomatoes, but few people are experimenting with them.)