Heat tolerant tomato varieties

[MissS]

With global warming making it difficult to grow tomatoes even in northern gardens I think it would be beneficial to make a list of heat tolerant varieties. It would be even better if they set in the heat and still tasted good.

Please list your known heat tolerant tomatoes with a short description.

[MissS]

JD's Special C-Tex - Black, RL, beefsteak with very good flavor.
Nairobi Nights - Purple, RL, beefsteak, mild rich flavor.

[karstopography]

This season has been hot, haha, it’s generally very warm to hot here once we get into well into May, and by northern standards, y’all might think much of April is also on the hot side. Anyhow, 95° has been about the tops here during the day, maybe a 96 or 97° day once or twice so far.

Nights, once we get into middle of May are generally trending above 70°up to and including sunrise. Most nights lows have been from 72-78° from late in May and all of June. If we got below 70° in that time frame it would be a very brief period.

I’ve still got a decent amount of fruit out there on the non-cherry plants, some recently setting fruit. To my estimation based on my above description of our recent weather, that’s good heat setting characteristics, but maybe the definition is more fluid than that. Overall, the fruit setting now is way below the prime days and nights in April and May where highs are more like low 80s and nights firmly in the 60s as a rule. But, the fruit setting has not completely shut down on the listed varieties below.

Heat setting ability Heirloom/OP types from 2022 are listed below. I’ll refrain for the most part on flavor comments as that’s pretty subjective and might also depend on climate, rainfall, temperatures, soil, etc. Obviously, some people don’t like some flavors that others enjoy.
Amana Orange
Kellogg’s Breakfast- huge, tall plant, but I barely pruned it at all.
Paul Robeson, pretty fruit, but not especially large tomatoes in my plot, rather compact growth habit, but still an indeterminate.
Hoy, a drier, large, low moisture, low seeds, low gel, meaty pink (clear skin) that’s, IMO, perfect for tomato and cucumber salad. Big, healthy plant with well protected by leafy cover large fruited with strong supporting stems.
1884, large pink, much sparser foliage than Hoy
Japanese Black Trifele, another low moisture, low seeds, tiny stem and insignificant core, that has become my favorite for salsa. Relatively Compact, productive, small fruit, yet indeterminate PL.
Black Krim, vigorous plant, productive, hands down the unequivocal favorite of discriminating squirrels.
Dragon’s Eye ( supremely prone to BER in my plot), strange foliage and growth habit, tons of distance between each leaf branch. Very tall.
Druzba
Giant Syrian.

For the most part, these plants listed have remained reasonably healthy in the heat. They do get bouts of leafy tree canopy filtered light along with direct sun.

[karstopography]

4483CF73-F115-440A-BABE-09283DC208CD.jpeg

0CFB61E5-6209-41B3-805B-0D5467F98430.jpeg

865A3D3F-43CD-4809-84D6-E34FEBF64E20.jpeg

401A81E2-EFF1-4322-AD72-64BD1598B583.jpeg

DFCCD92D-60B7-4A83-8EFC-6194E5E3A97A.jpeg

FF05E017-06A2-4ECC-89C6-291B9A3CFDE3.jpeg

E78E805A-62ED-4C9A-A6C2-7ED5236FF17A.jpeg

Photos might help to understand better the size and scope. Some plants have nearly ripe fruit that I didn’t take a photo of, mostly showing the newer sets and on some of the leafier ones, they are harder to find.

[mama_lor]

High vigor plants will usually tolerate better the heat. Also water well over night to better sustain the vegetative growth. And of course, fruit load is probably most important. Too many old varieties over produce on the lower levels, and have no more nutrients to send to the top. I think these principles are more important than the actual variety itself.

[PlainJane]

Well, no tomato I’ve ever tried survives a full Florida summer but I have this list of ‘pretty good’.

Maglia Rosa: elongated cherry with very good flavor, very productive. Anything still setting fruit in July is above and beyond for me.
Granda Oliver’s Chocolate: ripens to a deep brown, nice flavor. Was pleasantly surprised with how well it did. First time growing this year.
Daniel Burson: my favorite dark beef and although not still flowering it’s remained the healthiest looking. Pulled the last fruit yesterday.
Green Bee: Also from Fred Hempel, creator of Maglia Rosa and many other unusual tomatoes. Not everyone’s cup of tea with its crunchy texture but I like it. GWR cherry.

[karstopography]

@mama_lor I believe you have perfectly described the situation for heat tolerance. High vigor, deep watering, and plants with some “gas” remaining in the tank that didn’t burn it all up on the fruiting earlier in the season.

I’ve been feeding my plants also periodically, mostly that liquid Texas Tomato Food as a soil drench at watering time. Not every watering. Occasionally, the plants are getting a foliar application of mostly liquid kelp and I might put a bit of something like Texas Tomato Food diluted in addition to the kelp.

One thing that I have observed is that when I pull several color breaking fruit from a plant, that is when the plant decides to set some more fruit. There seems to be a maximum number or a ceiling on how many fruit that a plant can have on it at any one time, but when I pick several, the plant is free to then set more fruit.

But, right, I do agree it isn’t so much about the varieties, I do believe it is the factors you have listed in your post that are more important.

[mama_lor]

PlainJane, Green Bee is an incredibly vigorous plant, so much that I use it for grafting. Taste is good, but what was the problem for me was splitting, considering it needs to stay on the vine quite longer than normal tomatoes, the high sensitivity to splitting kinda negates all the good traits.
Atomic Fusion is also well above average in vigor while at the same time having a moderate fruit load per truss, so I think it could be a decent candidate to try for fruit setting in high heat.

[PlainJane]

@mama_lor, I’ve grown Atomic Fusion twice and just don’t care for the taste. I like Atomic Sunset much better for the same real estate.
Green Bee doesn’t split any worse than most everything else I grow so I just pull them off when they break and ripen indoors.
That’s them on the far side of the table.

E0472956-DBBD-4441-AA02-572763E922ED.jpeg

[Donnyboy]

I switched over to a truly heat tolerant hybrid two or three years ago. It is the only variety I grow today because it is not only heat tolerant, it is also very productive of large, perfect; red tomatoes which taste great. The only comparative taste I can relate is "old timey tomato taste"t

This year, I planted forty Heatmaster plants and replanted a number of Heatmaster volunteer plants from past years fallen tomatoes. They are supposedly "hybrid", but they sure make nice tomatoes.

This year, the Texas heat arrived before my plants had a decent head start. I watched my plants withering in the heat and bleaching out from the intense sunlight. The tomatoes were ripening when they were only one fourth their normal ripe size. I quickly installed some shade cloths over my beds and the plants started recovering with new growth in the shade and disregarding the 105 degree f daytime temps. My overall production has been damaged this spring, but the plants will regenerate in September and produce a good fall crop. It's amazing, but the Heatmaster plants are blooming and setting some fruit in the high heat, but protected from the deadly sun.

I germinated all of my Heatmaster plants this year and purchased a few (five or six) heirloom plants at a nursery to see how they would preform in the heat. The only heirloom I remember was Cherokee Purple. When the weather started getting serious about summer heat, the purchased heirloom plants seemed to rush to give up the ghost and die. I don't know a single gardener in my area who is having a successful gardening year due to the heat.

I wrote this post about nine thirty p.m. and the ambient temp outside is 94 degrees. It will be 84 or 85 degrees by sunrise.

[Shule]

My Snacker_ tomatoes seem to love the heat. The MKX_ tomatoes (B, B0, and B1) probably do, too (potentially even more), but I haven't evaluated those with as much attention (nor for as long). The MKX_ tomatoes (B, B0, and B1) have more seedling cold-tolerance and damping off tolerance, however.

Brandy Boy F11 sets fruit in the heat.

Roma, Matina, Galapagos Island, Sweet Orange Cherry, Amana Orange, my BSX crosses, Mountain Princess, Frog Princess, Marion, Picnic_ (and related tomatoes), Garden Leader Monster, Terhune, Nax_, Mexican Yellow (can get BER, though), Oroma (low production in my garden, though, but it sets in the heat!), Napoli, Aunt Ginny's Purple, Japanese Black Trifele, Burpee Gloriana, Sausage, Pruden's Purple, and Black Plum are some others. There are others.

In my area, I find that heat-tolerance is more important in early tomatoes and early midseason tomatoes (up to about 76 days), especially if they set all their fruit at once (unless they set it all before the heat kicks in; I don't know that I've ever seen that happen).

You have to be careful, since some tomatoes act like they're not heat-tolerant, but they're really just taking their time setting fruit. They may even drop blossoms and stuff. Maybe that's acclimatization working, though.

One thing I really think helps with regard to heat-tolerance is making sure my plants don't even need to be hardened off. If I can start them in full sun, and get them to grow fast early on post-transplant, that seems to give them a big advantage (even if they're small at transplant time).