Replacement Ideas for Growing Tomatoes?

I've been thinking about this a lot since I live in a Northern climate where the growing season is short (compared to say, Texas or California). And planning out my garden for the year. I'm trying to avoid wasted work if at all possible.

Does anyone know of a plant that is either perennial or very hardy in cold climates that could possibly be adapted to replacing tomatoes in recipes? We eat a lot of tomato sauce & I love cherry tomatoes in summer, but I feel like growing tomatoes is sometimes a ridiculous waste of time: sometimes you get a harvest of total abundance and other times it's too cold/rainy and the plants barely produce a few tomatoes before we get an early frost. This got me thinking: why am I trying to grow something that is wild to Mexico??? Same goes for peppers as well. Maybe i should try to adapt my diet to using no tomatoes, and if anyone has good suggestions I'm all ears. Perhaps there's a fruit that, when mixed with vinegar would taste similar. Maybe the only answer is either grow them & risk losing a lot of plants, or don't grow them and get over it, haha. Or just buy the darn things.

Would love any and all input! Thanks permies peeps!

My recollection of days in the Willamette Valley of Oregon was that tomatoes were grown in the valley for trucking to, and selling at, stands on the Oregon coast where tomatoes wouldn't grow....or at least wouldn't grow without help.  If you are on the coast of BC, I can imagine this situation even being worse.  What has astounded me in recent years is the plethora of large-scale ag/hort concerns that are under glass in northern climates.  Thus, in grocery stores in the US, it is no longer uncommon to see large bell peppers raised in Canada or the Netherlands....and I'm prettys sure tomato production in those industries is quite high as well:

https://www.npr.org/sections/thesalt/2016/06/16/473526920/how-canada-became-a-greenhouse-superpower

The story notes "The United States hasn't developed a big greenhouse industry because it didn't need to. It had all those warm-weather fields in Florida or California.....That's now changing as American growers go after the high-end tomato market."   But for a Permie, the other notion might be more along the lines of growing things in one's back yard that one never before could.

Is there any possibility of erecting even a small greenhouse for your tomato and/or pepper needs?  Even though we are not too far from the Canadian border, the frigid central Plains give way in the summer to excellent temperatures and long days for growing these in abundance.  What we don't have to contend with are the cooling summer breezes of the Pacific Ocean! :-)  Hope there may be something here helpful to your gardening interests.....

I can't think of a replacement.

I'd grow them against a south facing brick/block wall. I have trouble growing peppers here in SW Pennsylvania. This year I didn't even plant any pepper seeds for seedlings. I do well with tomatoes though. I quit buying seedlings and I quit growing hybrids. For you though I'd suggest a fast growing tomato like Early girl 59 days. I see a Summer Girl Hybrid that says 49-52 days in the Burpee catalog.

Something else I've quit doing is growing early tomatoes. I used to plant some beefsteak tomatoes and then plant early tomatoes to get some early. The year the first tomato I got was a beefsteak was the last year I planted the early tomatoes. I'm wondering if you might have similar luck doing the unexpected.

It's not a 1:1 sub, and maybe not even cold-climate appropriate, but I find myself using more winter squash puree now than tomatoes for things like chili and pasta sauces.  Last year was too cold and rainy for most of the tomatoes I planted (I'm in eastern PA, so I usually do so-so to okay with tomatoes in normal years), so I had some for fresh eating and that was about it.  It was a really horrible year all around; the only storage foods that produced in any appreciable quantity were green beans and one variety of winter squash.  Squash doesn't have the zing of tomato, but it has the umami and sweetness and a creamy texture that's a bit denser than tomato.  I don't know how it would be just on its own with added acid, but it plays nice with high-acid tomato sauce.  

There are probably other ways around tomatoes, like using a cream sauce or green pesto/ vegetable purees for things that need red sauce, or using berries and flowers in salads.  I'm really interested to see what this thread turns up.

My standard answer for things like this it to choose different genetics for the tomatoes that you grow. I can reliably grow tomatoes in my high-altitude, cold-nighted, short-season garden. It took trialing hundreds of varieties to find genetics that thrive in my location, and a bit of plant breeding. But I consider the investment well worth the trouble, because tomatoes are now one of the most straight forward and reliable crops that I grow. I sigh whenever someone sends me seeds of their favorite tomato: One more variety that is going to fail in my garden!

So...tomatoes are my favorite fruit, and of course I'm inclined to say there is no decent replacement.  But I think it might be a matter of taste.  

If you are considering replacing tomatoes with something else in the first place (which I think is as admirable as it is challenging), then it may possible to find something that will meet your need.

So, going back in my taste memory...what about tomatillos, and mix in a little something else, like a plum or two per quart of sauce?  Tomatillos are like weeds. I say that affectionately. I love tomatillos, though not as much as tomatoes. But I let some go to seed in my garden once.

They have a little of the zing of tomatoes, a somewhat similar texture, but none of the rounded sweetness.  Something like a plum might make the difference.  Not a super acidic plum, though.  Tomatillos are already very acid.  So the goal would be to add natural sweetness and some other sort of taste depth.

Two tomatoes were eaten as research for this reply. (Thanks for the excuse.  I'm going to go eat more now.)

Tomatillos that are harvested ripe -- after they have naturally fallen off the plant -- have a much different flavor profile than the hard/green tomatillos that are typically sold in stores.

See if you can get your hands on some Russian heirloom varieties. These are adapted to cool and short summers and have become popular in NZ in recent years because summers in many parts of both islands can be hit or miss. Locals called 2017 the year without a summer because it stayed cool and damp during the period we usually get some summer-like weather. In spite of this, my Russian tomatoes grew like gangbusters and put on a crop (this year they're even better, since we got more warmth).

These ones are doing well for me:

Black Krim is a large beefsteak type with a deep purplish colour and some green even when ripe.

Kibitz Ukraine is an oval fingerling variety with a really nice balance between sweet and tart...good in salads if they make it as far as the house.

Riesentraube is a largish cherry type with a little point on the end and is also known as "goat tit." Might be my favourite in terms of flavour.

My primary market tomato, and the foundation of my plant breeding efforts is a Russian variety named "Jagodka". It's about a 2 ounce red saladette tomato. Russian tomatoes in general haven't done all that well for me, but Jagodka in particular thrived in my garden.

Joseph Lofthouse wrote:Tomatillos that are harvested ripe -- after they have naturally fallen off the plant -- have a much different flavor profile than the hard/green tomatillos that are typically sold in stores.

I think some people who don't like tomatillos might like them if they found the "sweet spot" of ripeness for their tastebuds.  For me, I like to pick them when they are still on the plant, but have yellowed a little bit.  After they are on the ground awhile, some varieties get a musky flavor similar to cape gooseberry, which I find unappealing.  It's sweeter, but not likeable for me.

Great thing about tomatillos is they last for a really long time once picked.  They can sit in a bowl for a couple months until you use them, as long as they have their husks intact and don't get assaulted by fruitflies.  A remarkable fruit.

Phil, you hit on something that occurred to me.

I have the following Russian, or Eastern European beefsteaks growing from seed this year:

Rozovyi Gigant from Victory seed in Oregon a pink tomato

Crnkovic from Seed Savers Exchange in Iowa. This one is a Red Yugoslavian tomato

Also I have Marianna's Peace that I'm growing from seed I collected last year. I think this one came from Victory seed, it's a Czechoslovakian pinkish red tomato.

And I have a Giant Belgium from seed I collected, originally also from Victory Seed

From my experience the seed I save sprouts better than commercially sourced seed, which might be because it's getting accustomed to this area? I don't wash my seed, I pick it out of a tomato I'm eating and put in on a piece of paper towel and mark what the tomato was on the paper towel. They stick, I don't even put them in a envelope. Don't salt them though. You can tell a pink, red or yellow tomato from the color on the towel.



The spellings are correct.

Last year I tried direct seeding tomatoes in Western Montana and at least under last year's conditions it worked remarkably well. I searched for the shortest season tomatoes I could find.

Each year I get to try a different climate. In 2016 my weather was cold and wet. In 2017 decently warm but the smoke was thick for a very long time. Amurski Tigr, Bison, Ararat Flame all did well both years. However all were middle of the pack in 2017 when I tried direct seeding.

Fastest of the fast in 2017 were 42 days, tumbler f1, Anmore dewdrop, ditmarsher, Jagodka, sweet cherriette, forest fire, and krainiy sever. Also an ordinary Sungold f1 that I seed saved a second year so sungold f2 was right up there. Of these krainiy sever and forest fire have the largest tomatoes but take a little longer.

The strain of Jagodka I grew was because Joseph talked about it so much however I got my seed from another source in 17. I only ended up with one plant but it's fruits looked like some pictures on tatianas tomato database. However some of Joseph's Jagodka fruit pictures look larger and rounder. I am growing both strains of Jagodka this year just to see if they've diverged much.

In my experience there are substantially short season adapted tomatoes that can be reasonably grown fairly far north- definitely shorter and colder season places than my garden.

I've also grown tomatillos and they have about the same seasonality and a different flavor profile as tomatoes. From my explorations of tomatillos the last two years they may be underrated in their potentiality for short season gardens. Though if you really can't grow tomatoes I don't think tomatillos will work either. My fastest tomatillo was = to my fastest tomato not faster than.

however your question is about replacements.

There is a lot of potential to develop different cuisines. Pascal Baudar did this down in L.A. as a professional forager for chefs. There are some excellent books for foraging in the pacific northwest and you may find that with some study that there may be a number of plants that can be used to produce a tart sauce. These plants could include pacific crabapple, salmon berry, thimbleberry, raspberry, or rhubarb to name a few. The thing is none of these taste like tomatoes. They have their own flavors. One of Pascauls explorations was lemon subsitutes by foraging green fruits
https://www.amazon.com/New-Wildcrafted-Cuisine-Exploring-Gastronomy/dp/1603586067

You could extend this exploration of local cuisine possibilities to domestic plants as well as wild- whatever actually does well in your area and its very possible that a satisfying cuisine can be entirely locally sourced. I am sure you can recreate tart and satisfying sauces that might be good on pizza, pasta, and in all the various ways we use tomatoes. The flavor may just be very different from that of tomatoes.

So that's my thought, acceptable replacements may have similar features but different flavors and if you haven't already try the very shortest season tomato varieties available.

William Schlegel wrote:

however your question is about replacements.

There is a lot of potential to develop different cuisines. Pascal Baudar did this down in L.A. as a professional forager for chefs. There are some excellent books for foraging in the pacific northwest and you may find that with some study that there may be a number of plants that can be used to produce a tart sauce. These plants could include pacific crabapple, salmon berry, thimbleberry, raspberry, or rhubarb to name a few. The thing is none of these taste like tomatoes. They have their own flavors. One of Pascauls explorations was lemon subsitutes by foraging green fruits
https://www.amazon.com/New-Wildcrafted-Cuisine-Exploring-Gastronomy/dp/1603586067

You could extend this exploration of local cuisine possibilities to domestic plants as well as wild- whatever actually does well in your area and its very possible that a satisfying cuisine can be entirely locally sourced. I am sure you can recreate tart and satisfying sauces that might be good on pizza, pasta, and in all the various ways we use tomatoes. The flavor may just be very different from that of tomatoes.

So that's my thought, acceptable replacements may have similar features but different flavors and if you haven't already try the very shortest season tomato varieties available.

This could be an interesting experiment!  Last year I had hundreds of tomato seedlings and none of them matured in a crazy cool summer.  This year I'm not doing the annual garden as there's a lot of infrastructure work to do.  However, I have a lot of tart rhubarb, currants, and jostaberries that will come up on their own, and squash might give the sweet and umami flavors needed.

I was going to say that the tart fruits come in too early to be mixed with late squash, but now I'm reading about drying rhubarb so maybe it's possible to get everything synced up.  Is there a summer squash that would have the sweet/umami of something like a butternut squash?

Wow! So many wonderful responses.

Thanks everyone for taking the time to think about all of this. Ha, Kim I'm glad I could inspire a tomato snack!

I really appreciate hearing about the tomato varieties that have worked in short season areas and wet climates. That book by Pascal Baudar looks very interesting! I love the suggestion of crabapple, salmonberry, rhubarb. Maybe mixed with winter squash it could make a similar but unique flavor in savory dishes. I'm excited to try all of your ideas! And believe me, I wasn't looking to be fed an answer, I wanted to start a dialogue about replacing annuals that don't fit the climate. In my mind we've done that + covered some excellent ideas about adapting that plant to the local climate. I will give those Russian varieties (and varieties that william suggested) a try and also experiment with using local plants in our diet for different flavor profiles. I guess tomato is a pretty simplistic and easy base for a lot of dishes, so it will be a fun challenge to try new ways of incorporating perennials instead. Mmmm, I'm picturing nettle pesto, maybe cooking winter squash down to a paste & mixing raspberries for an interesting pizza sauce!

Morfydd St. Clair wrote:

This could be an interesting experiment!  Last year I had hundreds of tomato seedlings and none of them matured in a crazy cool summer.  This year I'm not doing the annual garden as there's a lot of infrastructure work to do.  However, I have a lot of tart rhubarb, currants, and jostaberries that will come up on their own, and squash might give the sweet and umami flavors needed.

I was going to say that the tart fruits come in too early to be mixed with late squash, but now I'm reading about drying rhubarb so maybe it's possible to get everything synced up.  Is there a summer squash that would have the sweet/umami of something like a butternut squash?

Every Sunday my friend and I cook together - we alternate picking recipes and meet up online.  Yesterday we experimented with this idea, trying to make a tomato-ish sauce that could go over pasta.  She used butternut squash and strawberries, and her verdict was:  "It was NOT a good combination.  The initial taste was good, but the aftertaste just ruined it."

I think mine was more successful.  It did't taste like tomato, but it would be a nice base for recipes.

Key ingredients:
-- Hokkaido pumpkin (because it's what the market had)
-- frozen rhubarb from last year
-- salt
-- black pepper

Strategy:
-- Tossed the squash into a cold oven and set it to 200 deg Celsius, turned the oven off after about 40 minutes and pulled it out 20 minutes later to continue.
-- Cut the squash in half, tossed the seeds.  The skin is edible and disappeared in blending.  I ended up with about 800 g squash.
-- Put the squash in the pot with some rhubarb, brought to a boil, started tasting.  Added water as needed to avoid scorching.
-- Blended with a stick blender periodically to make sure the rhubarb taste was mixed in.

At 200 g rhubarb, it could barely be tasted.  At 300 g, it was definitely there, and with a healthy dose of salt it was a nice sauce.  However, the boyfriend pointed out that you wouldn't put it over pasta because it was so bland.  At 600 g rhubarb, the flavor really popped!

I would say you could go to equal weights rhubarb/squash and have a nice fruity, umami sauce.

Notes:
-- Don't stint on the salt!  It really makes a difference.  (Tomatoes are salty in and of themselves, rhubarb and squash aren't.)
-- I assume my rhubarb broke down super quickly because it had been frozen and defrosted, breaking the cell walls.  You'd probably want to simmer it a few minutes while the squash roasted so you could just blend it together and be done.
-- I experimented in side bowls with garlic powder, cinnamon, and other spices.  The black pepper was the only one that made this taste more tomato-y.
-- To replace, say, spaghetti sauce, I'd also add oil (or meat), thin it out quite a bit with water, and use traditional italian spices.  A little will go a long way.

Now I'm enthusiastic to try this with red currants as the sour and plums or apples as the sweet!

We found Asian persimmon, especially a little unripe, to taste quite a bit like tomatoes, especially in salads and in tacos. They have a similar firm texture, too. And, they're a hardy perenial tree that supposedly will grow here! I used my birthday money to buy a tree this year, so hopefully we'll find that they do, indeed, do well here.

As for tomatoes, I only grow cherry tomatoes. I had a lot of luck with Sungold cherries. I like cherry tomatoes better than the big ones, and they ripen a lot sooner, which is good, because once the fall rains come, my tomatoes get blight and die.

I tried tomatilloes two years ago, but only got a few tomatillos, and most of them split before they were ripe. And then blight took them. THough I left lots of split ones to hopefully reseed, none of them did. Maybe it didn't get hot enough that year to get a good tomatillo harvest.

I've also heard of people using Autumn Olive and Goumi in tomato recipes. I've never tasted either, and have read that they;re a unique flavor but they do have lots of lycopeen (17 times the amount in tomatoes)... Here's a recipe for Autumn Olive ketchup: http://southernforager.blogspot.in/2014/08/autumn-olive-ketchup-great-recipe.html Here's a description of the flavor (https://hubpages.com/food/Wild-Autumn-Olive-Berries-for-Jams-and-Tomato-Sauce)

Autumn olive berries, more than anything else, taste like tomatoes—only a lot stronger.

You will probably not notice the tomato flavor if you eat the raw berries. The “tomato” flavor comes out in cooking, and its intensity alone makes it hard to recognize.

When the berries are cooked to make sauce, the house smells a lot like you are cooking tomato sauce. When small amount of autumn olive berry sauce is added to a soup, the soup will taste exactly as if tomatoes had been added to the soup. The main difference is, it takes much less autumn olive berry sauce than tomato sauce to provide this amount of flavor.

In another of my experiments in cooking with autumn olive berries, I made the sauce into spaghetti sauce and served it my teenage daughter and her boyfriend. The boyfriend could not tell any difference between the autumn olive berry sauce and regular tomato sauce.

My daughter and I could tell the difference. First, the flavor was far more intense. Second, there was a hint of tannins, as if a little black tea had been added to the sauce.

Another difference—to me, at least—was that the autumn olive berry sauce was far more filling. It’s almost as if the berries are so packed with nutrition that it takes far less to satisfy the appetite.

Nicole Alderman wrote:We found Asian persimmon, especially a little unripe, to taste quite a bit like tomatoes, especially in salads and in tacos. They have a similar firm texture, too. And, they're a hardy perenial tree that supposedly will grow here! I used my birthday money to buy a tree this year, so hopefully we'll find that they do, indeed, do well here.

As for tomatoes, I only grow cherry tomatoes. I had a lot of luck with Sungold cherries. I like cherry tomatoes better than the big ones, and they ripen a lot sooner, which is good, because once the fall rains come, my tomatoes get blight and die.

I tried tomatilloes two years ago, but only got a few tomatillos, and most of them split before they were ripe. And then blight took them. THough I left lots of split ones to hopefully reseed, none of them did. Maybe it didn't get hot enough that year to get a good tomatillo harvest.

I've also heard of people using Autumn Olive and Goumi in tomato recipes. I've never tasted either, and have read that they;re a unique flavor but they do have lots of lycopeen (17 times the amount in tomatoes)... Here's a recipe for Autumn Olive ketchup: http://southernforager.blogspot.in/2014/08/autumn-olive-ketchup-great-recipe.html Here's a description of the flavor (https://hubpages.com/food/Wild-Autumn-Olive-Berries-for-Jams-and-Tomato-Sauce)

Autumn olive berries, more than anything else, taste like tomatoes—only a lot stronger.

You will probably not notice the tomato flavor if you eat the raw berries. The “tomato” flavor comes out in cooking, and its intensity alone makes it hard to recognize.

When the berries are cooked to make sauce, the house smells a lot like you are cooking tomato sauce. When small amount of autumn olive berry sauce is added to a soup, the soup will taste exactly as if tomatoes had been added to the soup. The main difference is, it takes much less autumn olive berry sauce than tomato sauce to provide this amount of flavor.

In another of my experiments in cooking with autumn olive berries, I made the sauce into spaghetti sauce and served it my teenage daughter and her boyfriend. The boyfriend could not tell any difference between the autumn olive berry sauce and regular tomato sauce.

My daughter and I could tell the difference. First, the flavor was far more intense. Second, there was a hint of tannins, as if a little black tea had been added to the sauce.

Another difference—to me, at least—was that the autumn olive berry sauce was far more filling. It’s almost as if the berries are so packed with nutrition that it takes far less to satisfy the appetite.

Those are some great ideas, Nicole!  I have eleaegnus x Ebbingei that just went in last year - are the berries very different from autumn olive?

Morfydd, thanks for doing the experimentation with the pumpkin and rhubarb, salt & pepper! I never thought of combining those, but it sounds like it tastes pretty good. I will definitely give that a try this summer.

Nicole, that is amazing that autumn olive tastes so much like tomato! What a winner! That will be one of the first things I try, for sure. I'm excited that it works in your climate as it will likely work in mine. I was already planning on growing it as it's the only hardy olive for Canada that I know of. I bet it's packed with nutrition, like you said. Thanks, Nicole!

I had access to an abundance of Asian persimmon a year ago and froze many and made a batch of vinegar.  The vinegar turned out great.  Hadn't thought of making a tomato paste/sauce substitute.  As my own trees are just now coming into production I will have to try that.  I have Fuyu, Masomoto Wase Fuyu, Jiro, Maekawa Jiro, Izu, and Suruga varieties.  They are all non-astrigent and are very sweet.  A combination with something else may be required to acquire the tartness of a tomato for the paste or sauce.  They are a perennial tree and the harvest is late in the fall and early winter so making up sauce and paste would be at a less busy time.

I wish I could broaden the horizons of the people I feed to include pesto. Part of changing attitudes is accepting that you are *not* having spaghetti with tomato sauce, but a totally unique, nutritious and pleasant special meal that also uses pasta.

Nettle pesto is good and the leaves contain Vitamin D2. That's not as good as D3, but those of us living in the north need all the help we can get in the spring. It could be mixed with Borage as it self-seeds and is a good bee plant. Heck, you could probably sneak a few dandelion leaves in there also.

I hadn't considered growing persimmons in this cool, wet climate (I'm on the Wet Coast of Canada, also), but I will look into cold hardy varieties.

So far as tomatoes are concerned, even borrowing some land with much better sun than I get, the only tomatoes that did well were "Juliette". They are really a large mini-tomato rather than a small paste tomato even if that's what they look like, but they produced very well last summer and I intend to try them again this year. I made about a dozen 500ml jars of sauce with them which is sweeter than a paste tomato would have been, but it was pleasant and at least I knew where it had been grown. It was the first time I'd made sauce in a decade.

A local friend particularly likes Sasha's Altai which is a Russian tomato, so that supports comments made earlier. Her backyard gets more heat and sun than mine does.

If the only reason for substituting something for tomatoes was an aversion to the taste (or an allergy) I would suggest something exotically fruity like mangoes or tamarinds or even the distinctly unexotic peeled and cooked summer squash. The problem is that in this case, it is climatic factors that need to be considered, and most of the substitutes are probably going to need a warm to hot and humid climate which you don't have.

Of course, you may want different things depending on the recipe--fresh, diced tomatoes, purees, sauces, etc. so one thing may work well in some cases but not in others. If you could find a plant that would lend itself well to a basic puree, then add dices of something with a bit more texture might make a better solution than a single fruit or vegetable. I'm thinking that because it is so cold tolerant, sea buckthorn (Hippophae rhamnoides) might make a good sauce or puree because it has that essential acidity of tomatoes and easily makes juice. Then if you diced in something like a well-cooked, but somewhat bland squash for texture ... who knows?

After having said all that, however, I must say that I'm inclined to agree with everyone who says grow a better-adapted tomato and you won't have to substitute. I've grown quite a few "early" tomatoes in the past that fruited while the temps were still hovering in the mid-60s during the day with nights in the 40s, so there are definitely some cold-hardy varieties out there. Siberian and Glacier are two I can remember off the top of my head, but there are obviously more. I second the advice to look for Russian varieties--if they can handle the Russian climate, they are sure to do well anywhere in the USA. (And if you manage to get mature crops, SAVE THE SEEDS for replanting the next year. Working toward a landrace variety as Joseph Lofthouse recommends is really the way to go.)

From a culinary standpoint, what are you trying to replicate with the fauxmato?  Color?  Flavor?  or Usage?  
If you're trying to make a local, tomato free marinara or salsa recipe, there are likey plenty of options that are either indigenous or adaptable to your area.  They won't likely be nightshade-derivatives, but off the top of my mind, raspberries make an excellent salsa when mixed with chile peppers.  Similar fruits, not too sweet, and plenty of juice, should be feasible to mimic tomatoes if you bear in mind that the flavor won't be the same and the color might be off.  

From a horticultural perspective, given your climate, you may want to look at a multi-functional high tunnel.  Joel Salatin uses one to overwinter his poultry, utilizing deep bedding comprised of debris from his lumber milling and tree thinning throughout the year, with a layer of food waste and scratch grains.  The birds scratch continuously on the bedding, effectively creating an active composting mechanism.  When transplant season draws close, the birds are moved back out, and IF I UNDERSTAND CORRECTLY, they pull the compost out with a skid steer or tractor-mounted bucket.  The clever part is that the floor itself is not solid dirt, but rather has concrete slats with 4-6" gaps between them that are not finished... so the finished compost fills them, allowing for planting of tomatoes, etc.  When the season is done, the birds spend the winter cleaning out the plant material that doesn't compost with the addition of the new season's deep bedding.  

Not the most permie solution, but considering the overall inputs and outputs, I'd say it's not a bad approach.  Passive (human) inputs to create a high value compost for a Back to Eden or other style of garden.  

To my taste, cream and/or butter are a good substitute for most things. And with pasta, most definitely.

rhubarb makes a nice ketchup.

I love a good marinara but I also adore pesto, alfredo, and any other sauce that has garlic and basil, and/or butter and cream so replacing tomatoes in pasta dishes for me is not so much as making a sauce that tastes like tomato but having something completely different. I have a friend that sells pesto at the local farmer's market and her biggest seller (and it is scrumptious) is roasted beet.
However, your post and all the replies have really got me thinking!  I believe making a marinara type sauce has been covered really well by many above posts and given me so many new ideas too.
I wanted to add my 2 cents regarding ketchup and using rhubarb, as Renee mentioned above. I made something a couple years back called "Victoria Sauce" from the Ball Blue Book. I was looking for a way to use up excess rhubarb that wasn't a dessert (although it is a very sweet sauce) and it's in the book just below ketchup.
I was pleasantly surprised to discover that it was an excellent ketchup replacement. Main differences are that it's brownish and much thicker but of course the thickness could be altered if preferred. The texture and look is like apple butter.
If you're interested, I can post the recipe but I did just see several online when googled. It makes an excellent BBQ sauce as well and thinned out is a fabulous marinade.
My 93 year old co-worker has told me many stories of growing up with his grandparents in the northern woods of Idaho, and has mentioned more than once that "grandma made ketchup out of plums and it was delicious".
I'm sure it is; I figure the main elements of ketchup are sugar, vinegar, onion and spices, so whatever fruit is your base, is going to give you tasty ketchup-like results.
The base in Victoria Sauce is rhubarb and raisins, but the deer eat all my seedless grapes so no raisins here (maybe someday we'll put up deer fence).
Since both are plentiful around here, this year's ketchup will be made from a combination of plums and rhubarb.

Oh silly me, just realized some of my bumper crop of red currants would probably add the perfect balance of color and tang.
So, rhubarb, plums and CURRANTS!
I love this forum!

Alternatives to tomatoes that come to mind include (depending on your taste buds) tomatillos, ground cherries, litchi tomatoes, and parts of snake gourds. I recommend direct-seeding tomatillos and ground cherries, though. They seem to do better that way (as long as they sprout). Better yet, just get a tomatillo from another gardener and squish it where you want tomatillos next year. Till and water the soil when you want it to sprout. Tomatillos are commonly used for green salsa. I'm not sure that any of these crops will do any better in such wet conditions, but some of them might.

You can use several things as a replacement for tomatoes in ketchup (e.g. mushrooms, bananas, squash).

However, I think a better option than those might be to garden differently.

1. Get the right varieties of tomatoes. I might suggest some early ones like Nodak Early, Sub Arctic Plenty, Frosty F. House, Millet's Dakota, Cougar Red, and Gold Dust. You'll notice that Tatiana's is based out of British Columbia, Canada. She's one of the most popular names in tomatoes, and she's reviewed a lot of them; so, you might check her favorites.
2. Minimize the water. You might try laying black plastic down, which will both warm the soil and hopefully prevent most of the water from entering the soil. (Just be sure to support your tomatoes so they're not sitting in water.)

Just give them some protection with a cold frame at the start and tail end of the season and some milk jugs with warm water at night or in a larger cold frame a water barrel. I grew tomatoes in Alaska they actually do best with a slightly cooler summer than the deep south where they burn from the heat and they need some shade to produce during the mid day heat and sun. There are more than a few ways that you can use to push the zone in the spring and the fall when you need to help them a bit. you just need to step a bit out of the normal way of doing some thing to adjust and improve to local conditions for the plants.

I think the closest taste wise thing I could think of would be apple specifically cooked apple puree with a little bit of sugar, also has the sweet/sour balance and a comparable texture, and it grows in cold climates unlike many other suggestions.

Tomatoes here are greenhouse only things, we don't get warm enough outside away from a south facing wall.

William Schlegel wrote:
There is a lot of potential to develop different cuisines. Pascal Baudar did this down in L.A. as a professional forager for chefs. There are some excellent books for foraging in the pacific northwest and you may find that with some study that there may be a number of plants that can be used to produce a tart sauce. These plants could include pacific crabapple, salmon berry, thimbleberry, raspberry, or rhubarb to name a few. The thing is none of these taste like tomatoes. They have their own flavors. One of Pascauls explorations was lemon subsitutes by foraging green fruits
https://www.amazon.com/New-Wildcrafted-Cuisine-Exploring-Gastronomy/dp/1603586067

You could extend this exploration of local cuisine possibilities to domestic plants as well as wild- whatever actually does well in your area and its very possible that a satisfying cuisine can be entirely locally sourced. I am sure you can recreate tart and satisfying sauces that might be good on pizza, pasta, and in all the various ways we use tomatoes. The flavor may just be very different from that of tomatoes.

I always love seeing Pascal's name pop up! He is so inspiring. I've made his blackberry wine (and blackberry wine vinegar) for a few years now with the Himalayan blackberry that grows rampant around here. I wonder how blackberry would do as a tomato replacement? It is sweet and tart. Perhaps if you were able to add some savoury smokiness it could make a delicious sauce. You could juice them to prevent eating seeds if that's your preference. I personally enjoy them as a topping on pizza and sandwiches.

I will second a couple of points on here, first Asian persimmon, I always think of them as tree tomatoes. Even the structure is fairly similar. And also not trying to replicate something, by just making something else. My garden is too small to produce an entire year's tomatoes.  So for pasta we mostly switch to squash mac n cheese (puree your squash with full fat coconut milk, roasted garlic, salt, pepper, nutritional yeast or cheese, and my secret ingredient is a big spoonful of miso) and you have a very fast and healthy/tasty sauce, or an arugula and dandelion pesto. Both of these persist through the winter here so I can make a fresh batch every month or so. For curries we switch to Thai Green Curry or a tomato-less Indian curry like saag aloo. And plums make a great ketchup.

Mushrooms 🍄 ketchup 😋
Might be a good substitute for you.