AZ (SW/Hot/Dry) Tomato Ranchers

[Cornelius_Gotchberg]

I have pals way the HALE down in Tubac, AZ (https://en.wikipedia.org/wiki/Tubac,_Arizona_) who are looking for varieties, and tips for growing them, which would be expected to perform well there.

The Gotch

[Shule]

Well, it looks like the elevation is reasonably high there, so you'll want to take that into consideration. That probably means cooler-than-average nights (compared to the high temperatures of the days). So, you'll want varieties that don't drop blossoms easily when the temperature fluctuates.

Looking at the weather for this year it looks like it's probably similar to mine, temperature-wise (if not even a little cooler during the growing season; that's probably because of their higher elevation; but it's quite hot nonetheless).

It appears to be an exceptionally arid area (a lot more arid than my area, even). So, that's probably going to be one of the major challenges (much more so than the temperatures), especially if it has wind too (I don't know if it does), especially if it has fast-drying soil with low organic matter on top of that; lots of organic matter, and groundcover or mulch should hopefully help (or better yet, drip irrigation). It sounds like it's probably a very sunny area with a lot of clear skies; so, sunscald might be a problem, as might the roots getting too much sun exposure.

Plenty of fertilizer would probably help considerably, too. A well-fertilized plant can be a buffer against stress/heat-intolerance issues.

If they have a lot of calcium in their soil, I recommend a lot of nitrogen, even though tomatoes typically don't need a lot at a time compared to most plants. Calcium and nitrogen need to be balanced.

Also, an arid area like that probably has low nitrates in the soil (nitrates can come from rain). Nitrates are very helpful for production and growth. So, supplementing those somehow would probably help a lot.

A soil test would probably be pretty helpful. It might be one of those soils that has a high pH and is chalk full of calcium.

I'm guessing my Galapagos Island early yellow/gold cherry tomato would do much better than average there. It's not the same as the more popular tomatoes with Galapagos Island in their name that you see. Wintersown had it listed as a wild tomato (meaning S. cheesmaniae). I don't know if it is, but it's certainly a great tomato.

I would also recommend saving seeds from whatever varieties they grow, and growing them again. Acclimatization and selection should help many varieties to do better.

[Cornelius_Gotchberg]

@Shule, VERY detailed & helpful; will pass it along.

The Gotch

[slugworth]

I am going with Phoenix next year here.
They are supposed to be determinate type but are actually semi-determinate.
Got 1 plant indoors now under lights.
I sometimes go senile and forget to water it and it stays alive like the bee gees song.

[slugworth]

And the Phoenix stem has lots of warts, so it is easy to clone.

[habitat-gardener]

If I lived there, I'd check out Native Seeds/SEARCH
https://www.nativeseeds.org/collections/tomatoes
They have varieties that do well in the southwest.

I did an unintentional trial of varieties that do well in heat and drought this summer. We had many heat waves over 100F, and I watered each plant only 2-3 gallons every 10 days. Then, at the end of August, I installed drip irrigation. Though temperatures were getting less brutal, we still had heat waves. The plants got much more water with drip than from hand watering.
Most plants did not do well before drip. (Nematodes also kept many varieties from producing much.)

Benevento F1, however, produced big tomatoes through July and August. The seeds are pricey, but it's worth trying in harsh conditions. Most cherries also did ok -- Rosella, Green Bee F1, Black Cherry. Tommy Toe and Sun Sugar F1 did ok but really ramped up production with drip. The only other ones that were pretty consistent in the midst of heat waves were Raspberry Lyanna (semidet. or compact indet.), Bush Early Girl F1 (det.), and Cowboy (mine were 3-5 oz.). Kellogg's Breakfast produced the occasional large tomato.

[slugworth]

About 10 years ago Bonnie Plants sent Heatmaster plants up here by mistake.
That is supposed to be a hot weather type.
For determinate types you can stagger the plantings to stretch out the season.

[slugworth]

Tomato plants planted in clumps did well,the plants shade the ground and keep it cooler.
I've also let grass grow between the plants (the kind you have to mow) and the grass got diseased
instead of the plants.That is trickier in hot weather to keep the plants from getting buried in tall grass.
I still have green plants up here like the good old days.Plants that had good air flow look like the wicked
witches feet under the house.Neighbors lost their plants that were planted normally like weeks ago.